CA1095521A - Piperidinyl guanidines - Google Patents

Abstract

Abstract of the Disclosure Piperidinyl guanidines according to the invention which may be obtained by four different processes as described here-under may be used as agents for stabilising synthetic poly-mers against discoloration and degradation under the effects of visible and/or UV-light, heat and/or atmospheric influences.

Description

iQ9SS~l This invention relates to piperidinyl guanidines corresponding to the general formula (1):

X - -- C Z (I) In this general formula (I), X represents the radical:

I

~ '.
3 ~ ~ Rl CH3 N ~-~R

in which A represents hydrogen, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, an alkenyl or alkinyl radical having 3 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or the group -CH2-CHR4-OH where R4 represents H, methyl or phenyl;
Rl and R2 are the same or diiferent and each represents a straight-chain or branched alkyl radical having 1 to 12 carbon atoms, or ~1 and R2 together with the ring carbon atom to which they are attached form a cycloalkyl ring containing from 5 to 12 ring carbon atoms;
R3 represents hydrogen, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carhon atoms, an aralkyl ra~ical having 7 to 12 carbon atoms, a ~-cyanoethyl radical, a ~-alkoxy carbonyl ethyl radical having 1 to 3 carbon atoms in the alkoxy moiety, an aryl radical having 6 to 14 carbon atoms, the group -C~2-CHR40H, where R
Le_A ~ - 1 -~`~

.
. ~ ... .
. . I -- ~ -~ )9552~

represents H, methyl or phenyl, or the group:

CH3 ~ ~ 2 c~3 A~ Rl in which A, Rl and R2 are as defined above Z can have the same meaning as X or may represent a group -NUV where U and V are the same or different and have the following meaning:
H, a straight-chai.n or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carbon atomsS an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms and by Cl-C4-alkoxy, hydroxy or nitro groups or by chlorine or bromine atoms.
In addition, the radical U may represent a group R5-W
where R5 re]presents an aryl radical having 6 or 10 ring carbon atoms optio]nally substituted by chlorine, bromine, methyl or methoxy groups, a straight-chain or branched alkyl radical having 1 to 8 carbon atoms or an aralkyl radical having 7 to 12 carbon atoms~ W repreqents a C0- or S02-groupO
The radical Y represents a group of the general formula =N-R6 where R6 may have -the following meaning: H, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 7 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals containing 1 to 8 carbon atoms and by Cl-C4-alkoxy, hydroxy or nitro groups or by chlorine or bromine atoms.
Le A 16 8$9 -2-~9~5Zl However, R3, R6, U and V do not all represent hydrogen at the same time.
Compounds of the general formula (I) with the meaning defined above, in which 1, 2 or 3 radicals from the group R3, U and V represent hydrogen, may also be represented by the tautomeric formulae (II) and (III):
Y
X ~--Z X - C _ (II) (III) In this case, Y represents a group NHR6 where R6 is again as defined above.
The following are exa~ les of the radicals Rl and R2:
methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, n-hexyl, n-octyl, and n-dodecyl radicals, but preferably alkyl radicals having 1 to 4 carbon atoms and, with particular preference,methyl radicals.
The following are examples in which ~1 and R2 form a cycloalkyl ring with the ring carbon atom to which they are attached: spirocyclopentyl, spirocyclohexyl, spiromethyl-cyclohexyl, spirocycloheptyl and spirocy~lododecyl rings.
Rl and R2 preferably form a spirocyclohexyl ring.
Examples of A include hydrogen, the methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-hexyl, n-octyl, n-dodecyl, allyl, ~--methallyl, prop-2-inyl, benzyl, ~-methylbenzyl, ~-methyl benzyl, a-naphthyl methyl, ~-hydroxy ethyl, ~-hydroxy propyl or ~-hydroxy-~-phenyl ethyl group.
A preferably represents hydrogen or a straight-chain or branched alkyl radical having 1 to 4 carbon atoms, hydrogen and the methyl group being particularly preferred.
The following are examples of R3: ~, straight-chain or branched alkyl groups such as methyl, ethyl, isopropyl, n-butyl, sec-butyl, o~tyl or stearyl; hydroxy alkyl groups ~ss;~

such as ~-hydroxy ethyl, ~-hydroxy-~-methyl ethyl or ~-hydroxy-~-phenyl ethyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, methylcyclohexyl or cyclododecyl; aralkyl groups such as benzyl or phenyl ethyl; also the ~-cyanoethyl group and alkoxy carbonyl ethyl radicals such as 2-methoxy carbonyl ethyl, 2-isopropoxy carbonyl ethyl and aryl radicals such as phenyl, naphthyl, also alkyl~, alkoxy-, halogen- (Cl, Br, I) or hydroxy-substituted aryl groups, such as tolyl, tert-butyl phenyl, octyl phenyl, methoxy phenyl, butoxy phenyl, chloro-phenyl or hydroxy phenyl.
R3 preferably represents hydrogen, straight-chain or branched alkyl radic~ls having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl or oetyl; also cyclohexyl, methyl cyclohexyl, benzyl, ~-cyanoethyl,

2-methoxy earbonyl ethyl and ~-hydroxy ethyl. Hydrogen, methyl, cyclohexyl, benzyl, ~-cyanoethyl and ~-hydroxy ethyl are partieularly preferred.
~he following are examples of the radicals U and V:
H; alkyl radicals such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, dodeeyl or stearyl; cycloalkyl radicals such as cyelopentyl, cyelohexyl, methyl eyclohexyl or eyclododecyl; ar~lkyl groups sueh as benzyl, or phenyl ethyl; and aryl radical~ such a~
phenyl, naphthyl, also alkyl-, alkoxy-, bromine-, ehlorine-, hydroxy- or nitro-substituted aryl groups such as tolyl, tert-butyl phenyl, oetyl phenyl, methoxy phenyl, ehlorophenyl and hydroxy phenyl.
U and V preferably represent hydrogen, straight-ehain or branehed alkyl radieals ha~ing 3 to 8 carbon atoms, sueh ~s n-propyl, isopropyl, n-butyl, isobutyl, $ert-butyl, n hexyl or n-octyl; also the cyelohexyl radieal, the benzyl radieal and aryl radicals, sueh as phenyl, tolyl, tert-butyl phenyl, LQ_~ }~ 2 -4-~.

9~;S2~

chlorophenyl and naphthyl. n-Propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, cyclohexyl, phenyl, tolyl, tert-butyl phenyl, chlorophenyl and naphthyl are particularly preferred.
The following are mentioned as examples o~ the radical R5:
phenyl, chlorophenyl, bromophenyl, tolyl 9 methoxy phenyl, naphthyl, methyl, ethyl, propyl, isopropyl, benzyl: preferably aromatic radicals, of which phenyl, chlorophenyl, tolyl and methoxy phenyl are particularly pre~erred. ~he radical W
preferably repre~ents a carbonyl group.
Examples of the radical R6 include H, methyl, ethyl, isopropyl, sec-butyl, tert~butyl, n-dodecyl, tetradecyl, octadecyl, cyclohexyl, benzyl, phenyl ethyl, phenyl, naphthyl, chlorophenyl, bromophenyl, dichlorophenyl, nitrophenyl, tolyl, dimethyl phenyl and methoxy phenyl. ~ydrogen, alkyl radicals having 3 to 12 carbon atoms, such as n-propyl, sec-butyl, tert-butyl or n-dodecyl are preferred, as are cyclohexyl, phenyl, naphthyl, tolyl, chlorophenyl and nitrophenyl radicals.
H, phenyl, chlorophenyl, nitrophenyl and naphthyl radicals are particularly preferred.
The following are mentioned as examples of compounds corresponding to the general formula (I) &bove:
N,N'-dimethyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-dimethyl-N"-[1,2,2,6,6-pentamethyl-piperidinyl]-guanidine N,N'-diethyl-N"-[l-benzyl-2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-diisopropyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-isopropyl-N'-tert.-hutyl-N"-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-di-n-butyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-dioctyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-dioctyl-N"~ -hydroxyethyl-2,2,6,6 tetramethyl-piperidiny~
guanidine ~e A 16 8~ _5_ ~9S~l N,N'-didodecyl-N"-~2,2~6~6-tetramethyl-piperidinyl]-guanidine N,N'-distearyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-diphenyl-N"-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-diphenyl-N"-~1,2,2,6,6-pentamethyl-piperidinyl]-guanidine N,N'-bis-[p-chlorophenyl]-N"-[2,296,6-tetramethyl-piperidinyl]-guanidine N,N'-bis-[~-chlorophenyl]-N"-[l-allyl-2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-di-o-tolyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-di-m-tolyl-N"-[2,2,6,6-tetramethyl-piperidinyl~-guanidine N,N'-bis-[o,o'-diisopropylphenyl]-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-bis-[~-nitrophenyl]-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-bis-~p-methoxyphenyl]-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-dinaphthyl-N"-[2,2,6,6-tetramethyl-piperidinyl~-guanidine N,N'-dicyclohexyl-N"-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'~dicyclohexyl-N"-[1,2,2,6,6-pentamethyl-piperidinyl]-guanidine N-acetyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-butyryl-N'-[2,2,6,6-tetramethyl-piperidinyl~-guanidine N-phenyl-acetyl-N'-[2,2,6,6 tetramethyl-piperidinyl]-guanidine N~benzoyl-N'-[2,2,6,6 tetramethyl-piperidinyl]-guanidine N-benzoyl-N'-~1,2,296,6-pentamethyl-piperidinyl]-guanidine N-benzoyl-N'-methyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-p-chlorobenzoyl-N'-[2,2,6,6-tetramethyl-piperidinyl]- -guanidine N-p-chlorobenzoyl-N'-cyclohexyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-p-chlorobenzoyl-N'-[l-~-hydroxyethyl 2,2,6,6-tetramethyl-piperidinyl]-guanidine Le A 16 859 -6-, N-_-bromobenzoyl-N'-~2,2,6,6-tetramethyl-piperidinyl]-guan-idine N-o-methyl-benzoyl-N'-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N-a-naphthoyl-N'-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N-methylsulphonyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-~-methylbenzene-sulphonyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-phenyl-N',N"-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-phenyl-N',N"-dimethyl-N',N"-bis-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N-phenyl-N',N"-bis-[1,2,2,6,6-pentamethyl-piperidinyl]-guanidine N-2,5-dichlorophenyl-N',N"-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-3-nitrophenyl-N',N"-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-tolyl-N',N''-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-naphthyl-N',N"-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-methyl-N',N"-bis-[2,2,6,6~tetramethyl-piperidinyl]-guanidine N-cyclohexyl-N'N"-bis-~2,2,6,6-tetramethyl-piperidinyl3-guanidine N-phenylethyl-N',N"-bis-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-isopropyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-cyclohexyl-N'-[2,2,6,6-tetramethyl-piperidinyl]--guanidine N-phenyl-N1-[2,2,6,6-tetramethyl-piperidinyl3-guanidine N-phenyl-N'-[1,2,2,6,6-pentamethyl-piperidinyl]-guanidine N-E~chlorophenyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-p-tert.-butyl-phenyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine N-o-methoxy~ethyl-phenyl-N'-~2,2,6,6-tetramethyl-piperidinyl]-guanidine N,N'-dibutyl-N'-[2,2,6,6-tetramethyl-piperidinyl]-guanidine.
In another aspect, the invention relates to a process for the ~9 ~ _ 7 _ ~9S52~

preparation of piperidinyl guanidine compounds corresponding to the general formula (I) as described above and the corresponding tautomeric forms thereof which comprises:
(a) where a compound of for~Lla ~I) is desired wherein Z has the same meaning as X and R6 is not hydrogen, reacting a 4-aminopiperidine compound corresponding to the formula (IV):

CH3 ~ ~ (IV) CH3 Nl Rl A

(wherein Rl, R2, R3 and A are as defined above) with an isocyanide di-chloride corresponding to the formula (V):

/ Cl R7 - N = C \ (V) Cl ~`
(wherein R7 has the same meaning as R6 as defined above except for hydro-gen) at temperatures in the range of from -10C to 100C in the presence of solvents, f~om 2 to 4 moles of the 4-amino-piperidine of formula (IV) being used per mole of the isocyanide dichloride of formula (V), whereby there is obtained a piperidinyl guanidine corresponding to the general formula (VI):

~N-R7 R3 - N . C N - R

CH3 ~ ~ R2 CH3 ~ ~ R2 A A

(wherein A, Rl, R2, R3 and R7 are as defined above);
(b) where a compound of formula (I) is desired wherein R3 is hydrogen, R6 is not hydrogen and Z is -I~V wherein U is hydrogen and V is not hydrogen nor an araIkyl radical having 8 to 12 carbon atoms, reacting a ~ - 7a -;3L~95SZl 4-aminopiperidine corresponding to the formula (VII):

/~
CH ~ ~ R2 (VII) CH3 N Rl (wherein Rl, R2 and A are as defined above) with a carbodiimide correspond-ing to the formula (VIII):

R8 - N = C = N - Rg (VIII) (where.in R8 and R9 have the same meaning as R6 as defined above except for hydrogen) at temperatures in the range of from 20 to 200C whereby there is obtained a piperidinyl guanidine correspond-ing to the general formula (IX):

R8HN IlC ~1 N

~ (IX) CH3 ~ ~ R2 CH3 N Rl (wherein A, Rl, R2, R8 and R9 are as defined above);
(c) where a compound of formula (I) is desired wherein R6 is hydrogen and Z is -NUV wherein U and V are not C2 4 aIkoxy- nor hydroxy-substituted aryl radicals, reacting a 4-aminop:iperidine corresponding to the formula (XI):

,,,1,

3 ~ ~ R~ (XI) CH3 7 Rl A
(wherein Rl, R2, R3 and A are as defined above) with a cyanamide cor~

- ~ - 7b -, .

SSZl responding to the formula (XII):

lQ \
/ N - CN (XII) Rll (wherein Rlo and Rll are the same or dif~erent and represent H~ a straight-chain or branched aIkyl radical having 1 to 20 carbon atoms, a cycloaIkyl radical having 5 to 12 carbon atoms, an araIkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms, methoxy, nitro, chlorine or bromine atoms, or Rlo represents the group R5-W where R5 and W
are as defined above) in an organic solvent at terrlperatures in the range of from -10 to tlOOC, from 0.5 to 8 moles of the 4-aminopiperidine of formula (XI) being used per mole of the cyanamide of formula (XII)~ where-by there is obtained a piperidinyl guanidine corresponding to the general formula (XIII): NH

R3 - N - C - N \

I Rll (XIII) CH3 ~ ~ R2 , R1~ R2, R1o and Rll are as defined above) or (d) where a compound of formula (I) is desired where-in R6 is hydrogen and Z is -N W wherein U and V are not C2 4 aIkoxy- nor hydroxy-substituted aryl radicals and U is not R5-W, reacting a cyanamide correspond-ing to the formula (XIV):

~ 7c ,; , .

-:~9~

CH3 ~ ~ P'2 CH3 N Rl .

(wherein Rl, R2, R3 and A are as defined above) with an amine correspond-ing to the formula (XV):

NH (XV) Rll/
(wherein Rll and R12 are the same or different and represent H, a straight-chain or branched aIkyl radical having 1 to 20 carbon atoms, a cycloaIkyl radical having 5 to 12 carbon atoms, an araIkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by aIkyl radicals having 1 to 8 carbon atoms, methoxy, nitro, chlorine or bromine atoms) in an organic solvent at te~,peratures of from -10 to +100C, from 0.5 to 8 moles of the amine of formula (XV) being used per mole of the cyaraoide of formula (XIV), whereby there is obtained a piperidinyl guani.dine corresponding to the general formula (XIII):

R3 - N - ~ - N ~ R12 ~'~ Rll CH ~ ~ R2 (XIII) A
~ 1~ R2, R3, Rll and R12 are as defined above) Thus the invention provides for the production of 7d -.
~' ~ S52~

the compounds according to the invention by the ~ollowing methods:
1) 4-Aminopiperidines corresponding to the general formula (IV) are reacted with isocyanide dichlorides corresponding to the general formula (V). The reaction may be illustrated by reaction equation 1:

R3-N~

3 ~ -~2 ~ R -N=C ~ ' CH3 N ~1 Cl - 2 HCl (V) - (IV) IIN~7 R3N C ~ NR3 C1~3~R2 CH~2 (VI) Equation 1 The radicals A, Rl, R2 and R3 are as defined above. The radical R7 has the same meaning as the already defined radical R6 except for hydrogen.
The isocyanide dichlorides of the general formula (V) required as starting materials are known (cf. Angew. Chem 79, 663 to 680 (1967).
Reaction with the known 4-aminopiperidines corresponding Le A 16 85~ ~8~

l~9SSZ~

to general formula (IV) in accordance with the invention is carried out by initially introducing the 4-aminopiperidine in a solvent and adding the isocyanide dichloride dropwise thereto.
Suitable solvents are, for example water; alcohols such as methanol, ethanol or isopropanol; ethers such as diisopropyl ether, dioxane or tetrahydrofuran; hydrocarbons such as petrol, benzene, toluene or xylene; halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, chlorobenzene, and other solvents such as acetone, acetonitrile, ethyl acetate, glycol monomethyl ether, etc.
A quantity of ~asic compound e~uivalent to the quantity of hydrogen chloride liberated during the reaction is best added to the reaction mixture. Preferred bases are hydroxides, carbonates and oxides of the alkali and alkaline earth metals, sodium, potassium and calcium hydroxide being particularly preferred.
In one particularly preferred embodiment of the process, the reaction is carried out in a two-phase system consisting of an aqueous phase and an organic phase. The solvents used for the organic phase are water-immiscible organic solvents such as, for example, petrol, benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride, diisopropyl ether, etc.
The reaction is carried out at temperatures in the range of from -10C to +100C, preferably at te~peratures in the range of from 0C to 80C and, with particular preference, at temperatures in the range of from 0C to 50C.
From 2 to 4 moles, preferably 2 to 3 moles and, with particular preference, 2 moles of the 4-aminopiperidine may be used per mole of the isocyanide dichloride.
Le A 16 85~ -9-109S5;~i Substantially insoluble reaction products are separated off by filtration. Following removal of the solvent by evaporation, the reaction products remaining dissolved in the organic phase are optionally purified by recrystallisation or distillation.
The process may, of course, also be carried out continuously, for example in a tubular reactor, in a cascade of reaction vessels or in any other apparatus of the type commonly used for continuous processesO
2) 4-Aminopiperidines corresponding to the general formula (VII3 are added to carbodiimides corresponding to the general formula (VIII). The reaction may be illustrated by equation 2 below-R8HN-C~ R9 E~-N=C=N-R
A

(VII) (VIII) (IX) Equation 2 Compounds corresponding to the general formula (IX) may also be represented by the tautomeric formulae (IXa) and (IXb);

R N~C-NHR~
8 1 ~ R8HN-C=N-Rg NH NH

CH ~ R2 C~ ~ l2 C~3 N Rl CH3 IN Rl A ~ `-(IXa) (IXb) Le A 16 859 -10-~9~sz~

The radicals A, Rl and ~2 are as defined above. R8 and Rg may be the same or different and each has the same meaning as the already de~ined radical R6 except for hydrogen.
The carbodiimides required as starting materials are known compounds. They can be produced inter alia particularly easily from isocyanates (cf. J. A~er.Chem.Soc., 84, 3673 (1962).
They are pre~erably reacted with the known 4~amino piperidines by combining the reactants and leaving them to react with one another for a while at elevated temperature.
The reaction temperature is in the range of from 20C to 200C, preferably in the range of from 50C to 160C and, with particular preference, in the range o~ from 80C to 140C. The reaction time is in the range o~ from 1 hour to 24 hours, preferably in the range of ~rom 1 hour to 16 hours, a reaction time in the range of from 2 to 10 hours being particularly preferred.
The reactan-ts may be reacted with one another in any - quantitative ratios. It is preferred -to use fxom 1 to 1.5 moles of the 4-aminopiperidine and particularly preferred to use from 1 to 1.1 moles of the 4-aminopiperidine per mole of the carbodiimide.
The reaction may be carried out in a solvent which is inert under the reaction conditions. Solvents such as these are, for example, hydrocarbons such as cleaning spirit, toluene or xylene; also chlorobenzene, o-dichlorobenzene, glycol monomethyl ether acetate, dioxane, etc. ~owever, the reaction is preferably carried out in the absence of a solvent.
In general, the reaction is carried out under normal pressure, al-though it may also be carried out under reduced or elevated pressure. It may be particularly advantageous to Le A 16 859 11-~9SS;~

carry out the reaction under an elevated pressure of up to about 10 bars, more especially up to about 5 bars, in order to obtain a higher reaction velocity and a shorter reaction time.
In addition to the monomeric carbodiimides corresponding to the general formula ~VIII), polymeric carbodimides of the type which may readily be obtained from polyfunctional isocyanates in accordance with the method described in J. Amer. Chem. Soc.
84, 3673 (1~62), may also be used for the reaction. In this case the reaction may be carried out in the same way as described above.
If necessary, solid reaction products may be purified by recrystallisation, whilst liquid products are optionally purified by distillation in vacuo.
The process may, of course, also be carried out continuou-sly in an apparatus of the type commonly used for continuous processes.
3) 4-Aminopiperidines corresponding to the general formula (XI) are reacted with cyanamides corresponding to the general formula (XII). The reaction may be illustrated by equation 3:

Rlo /1\ R
CX3 ~ ~ ~ + ~N-CN ~ C~3 ~ ~ X

(XI) (XII) (XIII) Equation 3 The radicals A, Rl, R2 and R3 are as defined above, the radicals Rlo and Rll may be the same or different and each represents hydrogen, a straight-chain or branched alkyl _~ L~ 5~ -12-LC~95S2~

radical having 1 to 20 carbon atoms, a cycloalkyl radical ha~ing 5 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical ha~ing 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms, also by methoxy or nitro groups and, in addition, by chlorine or bromine atoms. In addition, the radical Rlo may represent the group R5-W of which the meaning has been defined above.
Cyanamides of the general formula (XII) are either known or may readily be obtained by methods known from the literature (cf. S. Petersen in Houben-Weyl-Muller, Methoden der Org. Chemie, 4th Edition, Vol VIII, page 173).
Their reaction with the known 4-aminopiperidines corresponding to the general formula (XI) is generally carried out in an inert organic solvent at temperatures in the range of from -10C to +100C and preferably at temperatures in the range of from O to 80C9 temperatures in the range of from 0C to 50C being particularly preferred. Suitable organic solvents are, for example, hydrocarbons such as petroleum ether, pentane, cyclohexane, benzene, toluene xylene, etc; also chlorinated compounds such as methylene chloride, chloroform, carbon tetrachloride or chlorobenzene;
it is also possible to use ethers such as, for example, diisopropyl ether, dioxane, tetrahydrofuran and dimethoxy ethane. Tetrahydrofuran, dioxane and toluene are particularly preferred.
The reaction components may be added in hny order. From 0.5 to 8 moles, preferably from 0.~ to 1.5 moles and, with particular pre~erence, from 1 to 1.2 moles of the 4-amino piperidine are used per mole of the cyanamide. The reaction time is in the range of from 10 minutes to 20 hours and prefer-ably in the range of from 30 minutes to 10 hours.
Le A 16 859 -13-' lO9SSZ~

In general, it is not necessary to start with the pure cyanamides. It is advantageous to start with the amines on ~hich the cyanamides are based, to react them with cyanogen chloride or cyanogen bromide, as known from the literature, and then to react the cyanamides obtained in this way, without further purification or intermediate isloation, with the 4-aminopiperidines corresponding to the general formula (XI).
In general, the reaction is carried out under normal pressure, although it may also be carried out under reduced or elevated pressure. It can be advantageous to carry out the reaction under an elevated pressure of up to about 10 bars, more especially up to about 5 bars, in order to obtain a higher reaction velocity and a shorter reaction time.
The process may, of course, also be carried out continuously in an apparatus of the type commonly used for continuous processes.

4) Another variant of the production of compounds corresponding to the general formula (XIII) comprises reacting cyanamides of the general formula (XIV) with amines corresponding to the general formula (XV). This reaction is illustrated by reaction equation 4:

R -N-CN ¦l / R~2 CH~ ~ ~2 NH ____~ CH~
CH3 I Rl Rll CH3 N R
A A
(XIV) (XV) (XIII) Equation 4 '~
Le A 16 859 -14-z~

The radicals A, Rl, R2 &nd R3 are as defined above. The radicals R12 and Rll have the same meaning as Rlo and Rll in equation 3, except that in equation 4 R12 does not represent the group R5-W.
Cyanamides corresponding to the formula XIV are produced by reacting cyanogen chloride with aminopiperidines in accordance with equation

5:

R3NH R3 - Nl - CN

3 \ ~ ~ R +C1CN -3 CH ~ ~1 CH3 N Rl CH3 N R2 A A

Equation 5 me radicals Rl, R2, R3 &nd A are as already defined.
The cyanogen chloride is reacted with the known piperidine derivatives by initially introducing the piperidine derivative in an inert organic solvent, adding one equiv~lent of a base for bind-lng the hydrogen chloride formed during the reaction and then adding the cyanogen chloride dropwise at temperatures in the range of from -20C to +10C and, with particular preference, at temperatures in the r&nge of from -5C to +5C.
From 0.5 to 2.0 moles, preferably from 0.9 to 1.2 moles &nd, with particular preference, 1 mole of the piperidine derivative is used per mole of cyanogen chloride.
Examples of suitable bases are tertiary amines such as, for example, trilnethyl amine, triethyl amine or N,N-dimethyl benzyl amine, also carbonates, oxides &nd hydroxides of the alkali and aIkaline earth metals.
It is preferred to use hydroxides of the aIkali and aIkalirle earth metals, sodium and potassium hydroxide being ~ - 15 _ ~9~S;~

particularly preferred.
Suitable inert organic solvents, in which the reaction according to the invention may be carried out, are for example petroleum ether, pentane, hexane, cyclohexane, benzene, toluene, xylene, chloro~enzene, o-dichlorobenzene~
methylene chloride, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and dimethoxy ethane.
In one preferred variant, the reaction is carried out in a 2-phase system consisting of an aqueous phase and an organic phase. The organic phase consists of the piperidine derivative used as starting material and optionally an inert water-immiscible organic solvent such as, for example, petroleum ether, pentane, hexane, cyclohexane, benzene~
toluene, xylene9 chlorobenzene, o-dichloroben~ene, methylene chloride, chloroform, carbon tetrachloride, diisopropyl ether, 1,2-dichloroethane, 1,2-dichloropropane, trichlorethylene, etc.
Substantially insoluble reaction produc~s are separated off by filtra-tion. Following removal of the solvent by evaporation, reaction products which have remained dissolved in the organic phase are purified either by distillation or by re~rystallisation.
In general, the reaction is carried out under normal pressure. However, it may also be carried out under reduced pressure or under an elevated pressure of up to about 10 bars, preferably up to about 2 bars.
The process may, of course, also be carried out continuously, for example in a tubular reactor, in a cascade of reaction vessels or in any other a~paratus o~
the type commonly used for carrying out continuous processes.
In general, the cyanamides are reacted according to ~qua-tion 4 with the amines in an inert organic solvent at tempera-~ç 4 16 8~ -16-55;~1 tures in the range of from -10 to +100C and pre~erably at tem-peratures in t~e range of from 0 to 80~, temperatures in the range o~ from 0 to 50C being particularly preferred. Examples of suitable organic solvents are hydrocarbons such as petroleum ether, pentane, cyclohexane, benzene, toluene, xylene, etc; also chlorinated compounds such as methylene chloride, chloroform, carbon tetrachloride or chlorobenzene; in addition, it is possible to use ethers such as, for example, diisopropyl ether, dioxane, tetrahydrofuran and dimethoxy ethane.
Tetrahydrofuran, dioxane and toluene are particularly preferred.
The reaction components may be added in any order.
From 0.5 to 8 moles, preferably from 0.9 to 1.5 moles and, with particular preference, ~rom 1 to 1.2 moles o~
the amine m~y be used per mole o~ the cyanamide. The reaction time is in the range of from 10 minutes to 20 hours and preferably in the range of from 30 minutes to 10 hours.
In general, the reaction is carried out under normal pressure, although it may also be carried out under reduced or elevated pressure. It may be particularly advantageous to carry out the reaction under elevated pressures of up to about 10 bars, more especially up to about 5 bars, in order to obtain a higher reaction velocity and shorter reaction times.
The process may, of course, also be carried out continuou-sly in an apparatus of the type commonly used ~or carrying out continuous processes.
The compounds according to the invention may be used to stabilise synthetic polymers against degradation.
The expression "synthetic polymers" covers the ~ollowing products among others: polyurethane, pol~ethylene oxide polymers, polypropylene oxide polymers, polyepoxide polymers, polyamides, ~or example nylon 4, nylon 6, nylon 11, nylon 12, Le ~ 16 8~ -17-~9~Z~

nylon 6,6J nylon 6, 10 or copolyamides of the above components; aromatic polyamides of, for example, isophthalic acid and terephthalic acid, m-phenyl-ene diamine and/or _-phenylene diamine; polyesters such as polyethylene terephthalate, polybutylene terephthalate or segmented copolyether esters of dihydroxy polytetramethylene oxide, terephthalic acid/isophthalic acid ethyl-ene glycol/1,4-butane diol or 1,4-cyclohexane diol; polycarbonates, poly-imides, plastics based Oll cellulose such as, for example cellulose acetate, cellulose butyrate or polyacetals such as polyoxymethylene; polyolefins such as polyethylene of low or high density, polypropylene, polystyreneJ polybuta-diene, polyisoprene, polypentenamers, polyacrylonitrile, also homopolymers ofother olefins and copolymers, such as ethylene/propylene copolymers, ethylene/
propylene diene copolymers, ethylene/butylene copolymers, ethylene/vinyl ace-tate copolymers, styrene/butadiene copolymers, styrene/acrylonitrile copoly-mers, acrylonitrile/butadiene/styrene copolymers; polyvinyl chloride and poly-vinylidene chloride; copolymers of vinyl chloride with vinylidene chloride and copolymers of vinyl chloride and vinylidene chloride with vinyl acetate and other olefins such as, for example, acrylonitrile; and unsaturated poly-ester resins.
One particularly important group of polymers to be stabilised are the elastic polyurethanes which may optionally be present in foamed form and which may be produced by methods known per se from conventional starting materials. The polyurethanes are generally obtained by reac~ing relatively high molecular weight polyhydroxyl compounds ~for example polyesters or poly-ethers with a molecular weight of about 500 to 5000 and melting points prefer-ably below 60C) and aliphatic, araliphatic or aromatic ~09S52~

polyisocyanates (preferably aromatic diisocyanates, such as tolylene diisocyanate or diphenyl methane-4,4'~diisocyanate), also so-called chain-extending agents, i.e. low molecular weight compounds (molecular weight for example 18 to 400) containing 2 or more isocyanate-reactive groups (for example water, low molecular weight diols, diamines, dihydrazides or similar compounds, such as for example amino alcohols, aminohydrazides, hydroxy hydrazides, aminosemicarba~ides, semicarbazide hydrazides, semicar'bazide carbazinic esters or corresponding mixtures of these chain-extending agents produced in one or several stages either in the melt or in solvents by a number of known and modifiable processes.
The following are mentioned as examples of starting materials for prod~cing the polyurethanes: polyesters of adipic acid and dialcohols having from 2 to about 10 carbon atoms, pre-ferably those with more than 5 carbon atoms, the dialcohols also being usable for lowering th~ melting points of the polyesters in the mixture; poly~sters of caprolac~one and dialcohols, also polyalkylene ether diols, especially polytetramethylene ether diols, polytrimethylene ether diols, polypropylene glycol or corresponding copolyethers Preferred diisocyanates are aromatic diisocyanates such as diphenyl methane-4,4'-diisocyanate, tolylene diisocyanate, araliphatic diisocyanates such as m-xylylene diisocyanate or even aliphatic diisocyanates, such as hexamethylene diisocyanate and dicyclohexyl methane-4,4~-diisocyanate~ These starting materials are reacted, optionally with additional dialcohols, to form N~0-preadducts which preferably have the structures indicated in Belgian Patent Specification No. 734,194. Suitable chain-extending agents) which may optionally be used in admixture or in a multistage reaction, are water and/or dialcohols or trialcohols, such as butane diol and ~-xylylene glycols, trimethylol propane, Le A 16 ~59 -19-,.
: ' l~9SS2~

aminoalcohols such as ethanolamine, diamines such as diphenyl methane-4,4'~diamine, 3,3'-dichlorodiphenyl methane-4,4'-diamine, but preferably aliphatic diamines such as ethylene diamine, l,2-propylene diamine, isophorone diamine, metaxylylene diamine and hydrazine or dihydrazides, such as carbodihydrazide, oxalic acid dihydrazide, glutaric acid dihydrazide, pimelic acid dihydrazide, terephthalic acid dihydrazide, ~-alanyl hydrazide or semicarbazide hydrazides, such as ~-semicarbazide alanyl hydrazide.
It is preferred to stabilise polyurethanes which, in addition to urethane groups, also contain -NH-CO-NH-groups formed by the reaction of isocyanate groups with water and/or with compounds containing terminal NH2-groups (~or example diamines, dihydrazides, carbodihydrazide, semicarbazide hydrazides or hydrazine~ and which have a substantially linear, segmented molecular structure, are soluble in highly polar solvents, such as dimethyl formamide or dimethyl acetamide, before they are formed or shaped and of which the characteristic segments may be characterised by the following formula moiety: _ ~ Y.NH.CO.NH.X.NE.CO.NH ~ , This segment may be for~ed ~rom the reaction o~ an NCO-preadduct OCN.Y.NCO with a chain-extending agent H2N.X.NH2.
The radical -Y- of the NCO-preadduct may be built up, for example, as follows:
-R.NH.CO.O.D.O.CO.NH.R.-or may have any other conventional composition (c~. Belgian Patent Specification No. 734,1~4).
In the above formula, R represents a difunctional aliphatic, araliphatic or aromatic radical (of a diisocyanate~.
D represents the radical oY a relatively high molecular weight polyhydroxyl compound with a molecular weight in Le ~ 16 859 -20-~ 5~21 the range of from 500 to 5000 and with melting points below 60C without its terminal hydroxyl groups (for example the radical of a polyalkylene ether, polyester, polyacetal or poly-N-alkyl urethane). X is the radical of a di-functional chain extender containing terminal NH2-groups without the terminal NH2-groups, for example an aliphatic, araliphatic, aromatic or heterocyclic radical, an -HN-C0-alkylene-C0-NH-radical, an -NH-C0-NH-(CH2)2-C0-NH-radical or a bond between two n-atoms. The synthesis of polyurethane (ureas) of this type is described in detail, for example in German Auslegeschrift No.
1,270,276, and in Belgian Patent Specification No. 734,194. Polyurethane foams can be produced, for example with the stabilisers added to the starting components (for example polyethers), by known methods and according to known recipes (cf. for example Kunststoff-Handbuch, Vol VII, Polyurethane, Carl Hanser Verlag Munich, 1966, pages 440 to 457, 504 to 531).
By virtue of their outstanding properties, the synthetic polymersi are widely used for example as filaments, fibres, films, lacquers or sheeting.
Unfortunately, one disadvantage of these synthetic polymers is their poor stability to light and heat. Polyolefin, polyamide and polyurethane elastomers, for example, undergo considerable degradation under the effect of light and heat, as reflected in the loss of their favourable mechanical properties and also in occasionally very considerable discoloration.
Accordingly, a number of different stabilisers, such as for example phenol derivatives, benzophenone compounds or derivitives of benztriazole, have been proposed for stabilising these synthetic polymers. Unfortunately, these products are not entirely satisfactory.

, ~09SiS2~

The compounds corresponding to the general formula (I) provide synthetic polymers with an excellent degree of protection against degradation.
The stabilisers are used in particular for stabilising synthetic polymers against discoloration and degradation under the effects of visible and/or UV-light, heat and/or atmospheric influences such as oxygen, oxides of nitrogen, chlorine and exhaust combustion gases.
The compounds of the general formula (I) used as stabili-sers may readily be incorporated into the synthetic polymer by any of the standard processes for compounding additives in a polymer. For example, the liquid, molten or solid powder-form stabiliser may be mixed with the synthetic polymer or may be mixed in the form of a solution, suspension or emulsion with a melt, solution, suspension or emulsion of the synthetic polymer. Mixing may optionally be carried out during the actual prepara-tion of the polymer. In the case of filaments, the stabiliser may even be applied to the surface in the form of a melt of the preparation or may be incorporated during wet spinning from the coagulation bath with the filaments in gel form.
The quantity in which the stabiliser in accordance with the invention is u~ed is governed by the type and particular application of the polymer and may be left to the discretion of the average expert. In general, the stabiliser i9 used in a quantity of from 0.01 to 5% by weight, preferably in a quantity of from 0.05 to 3.5~0 by weight and, with particular preference, in a quantity of from 0.05 to 2.5 by weight, based on the quantity of the polymer.
In addition to the stabilisers, other known additives may be incorporated in the polymer. Additives such as these include antioxidants of the sterically hindered phenol type such as, for example, 2,6-di-tert-butyl-Le ~ 16 85~ 22-1~9S~

p-cresol; 4,4'-thiobis-(6-tert-butyl-3-methyl phenol; 2,2'-thiobis-(6-tert-butyl-4~methyl p~enol); ~,a'-bis-(2-hydroxy-3,5-dialkyl phenyl)-~-diisopropyl benzenes; ~,~'-bis-(2-hydroxy-3,5-dialkylphenyl)-m-diisopropyl benzenes, 2,2'-methylene-bis-(4-methyl-6-tert-butylphenol); 2,2'-methylene-bis-(4-methyl-6-cyclohexyl-phenol); 1,1,3-tris-(5-tert-butyl-4-hydroxy-2-methylphenyl)-butane; tetrakis-(3,5-di-tert-butyl-4-hydroxy phenyl propionyl oxymethyl)-methane; also compounds of divalent sulphur such as, for example, dilauryl thiodipropionate;
compounds of trivalent phosphorus such as, for example, triphenyl phosphite, tris-(~-nonylphenyl)-phosphite, and UV-absorbers based on 2-(2'-hydroxyphenyl)-benzotriazole such as, for example 2-(2'-hydroxy-5'-methylphenyl)-benzo-triazole, 2-(3',5'-di-tert.-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole; or even UV absorbers based on benzo-phenone such as, for example 2-hydroxy-4-octoxy benzophenone;
2',4'-di-tert.-butylphenyl-3,5-di-tert.-butyl-4-hydroxy-benzoate; cyanoacrylic acid esters such as, for example, a-cyano-~-methyl~ -methoxyphenyl)-acrylate and other light stabilisers such as, for example, 2,2'-thiobis-~4-tert.-octylphenolate)-n-butylamine nickel.
The object of the following Examples is merely to illustrate the invention. The structures of the compounds are clearly identified by their nuclear resonance and mass spectra. M+ is the abbreviation for the mass of the mole ion in the mass spectrum. All parts and percentage~ are by weight un-less otherwise indicated.
EXAMPl.E 1 : ~ =
N?N'-Dicyclohexyl-N"-[2,2,6,6-tetramethyl-piperidinyl~-~uanidine 51.5 g of dicyclohexyl carbodiimide and 44.5 g of 4-amino-2,2,6,6-tetramethyl piperidine are mixed and the mixture is subsequently heated for 6 hours to 140C in the absence of air and moisture. The volatile constituents are th~n distilled o~f in a high vacuum. After cooling, 82 g of the title compound are obtained in the form of a yellow resin.
C22H42N4(362.6) observed M+ 362 N-Isopropyl-N'-tert.-but~l-N"-~2,2,6,6-tetrameth~l piperidin~
~0 uanidine 14.0 g of N-isopropyl-N'-tert-butyl-carbodiimide and Le ~ 16 8~ -23-~095S2~

21.3 g of 4-amino-2,2,6,6,-tetramethyl piperidine are mixed and heated for 8 hours to 120C in the absence of air and moisture. The reaction mixture is then fractionated in a high vacuum, giving 17 g of the title compand in the form of a colourless liquid boiling (bpo 03) at 110C.
C17H36N4 ~296) observed M+ 296 E KAMPLE ~
N,N~-Diphenyl-Nll-[2! 2! 6,6-tetramethyl piperidi~l]-~uanidine 44.5 g of 4-amino-2,2,6,6,-tetramethyl piperidine are slowly added dropwise to 38.8 g of diphenyl carbodiimide~
The mass formed during the exothermic reaction is heated for 1 hour to 140C, subsequently cooled and boiled twice with cleaning spirit. After filtration and drying, 60 g of the title compound are obtained in the form of a colourless powder melting at 170C.
C22H30N4 (350.5) observed M~ ~50 EXA~LE 4 N,N'-Bis-[o,o~-diisopropylphenyl]-N"-[2,2,6,6,-tetramethyl-piperidin~ uanidine 72.5 g of bis-(o,o~-diisopropylphenyl)-carbodiimide and 34.1 g of 4-amino-2,2,6,6,-tetramethyl piperidine are mixed and the mixture is heated for 10 hours to 140C.
Volatile fractions are then distilled off in a high ~racuum at 140C and the residue is cooled, giYing 104 g of the title compound in the form of a yellow resin.
C31~Hs4N4 (518-8) observed Ml 518 EXAMPL~
N,N'-Bis-[~-chloropheny:L]-N~'-[2,2,6,6-tetramethyl piperidinyl]-~uanidine 44.5 g of 4-amino-2,2,6,6-tetramethyl piperidine are added dropwise to 52~6 g of bis-[p-chlorophenyl]-carbodiimide, The mixture is stirred for 10 hours at 140~C and subsequently - 2~ -S~

fractionated in a high vacuum, leaving 43 g of the title compound in the form o~ a ye~lowish liquid boiling (bp 0 02) at 180C which crystallises slowly.
C22H28C12N4 (41904) observed M+ 418 for 35Cl N,N'-Bis-[o-methylphenyl]-N"-[2,2,6,6-tetramethyl piperidinyl~-uanidine 44.5 g of 4-amino-2,2,6,6-tetramethyl piperidine are added dropwise to 44.2 g of bis-[o-methylphenyl]-carbodiimide~
The mixture is stirred for 10 hours at 120C and the volatile constituents are subsequently distilled off in a high vacuum at 140C. After cooling, the compound is obtained in the form of a yellowish resin in a yield of 68 g.
C24H34N4 (378.6) observed M 378 EXAMPLE Z
Example 7 describes the production of a polymeric guanidine from a polymeric carbodiimide.
13.1 g of a polymeric carbodiimide, produced from a mixture of 80 parts of 2,4-tolylene diisooyanate and 20 parts of 2,6-tolylene diisocyanate by the method described in J0 Amer. Chem. Soc. 84, 3673 (1962), are dissolved in 50 ml of toluene. 35 g of 4-amino-2,2,6,6-tetramethyl piperidine are added to the resulting solution. The solution is stirred for 1 hour at room temperature and then under reflux for 4 hours. Thereafter the solvent is distilled off in vacuo and the residue is freed in a high vacuum from the remaining volatile constituents. 44 g of polymeric guanidine are obtained in -the form of a light brown resinO
E _ ~
14.6 g of benzoyl oyanamide are suspended in 100 ml of toluene, followed by the gradual dropwise addition with Le A 16 859 - 25 -iC~9~SZl stirring of 17.2 g of 4-amino-2,2,6,6-tetramethyl piperidine.
After stirring for another 5 hours at 50C, the mixture is left to cool and is then filtered under suction. After drying, 23 g of the title compound are obtained in the form o~ a colourless powder melting at 168 to 170C.
C17H26N40 (302.4) observed M~ 302 N-o-Methylbenzoyl-N~- L2. 2~6,6-tetramethyl piPeridinyll-uanidine 50.2 g of N-o-methylbenzoyl-N'-[2,2,6,6-tetramethyl piperidinyl]-guanidine, a colourless powder melting at 138-140C, are obtained in the same way as in Example 8 from 32 g of o-methylbenzoyl cyanamide and 31,5 g of 4-amino-2,2,6,6-tetramethyl piperidine in 200 ml of toluene.
C18H28N40 (316-5) observed M~ 3~6 N-P-Methoxybenzoyl-N~-L2l2~6.6-tetramethyl Dl ~uanidine 62.4 g of N-~-methoxybenzoyl-N'-~2,2,6,6-tetramethyl piperidinyl]-guanidine9 a colourless powder melting at 160 to 163C, are obtained in the same way as described in Example 8 from 35,2 g of ~-methoxybenzoyl cyanamide and 31.5 g of 4-amino-2,2,6,6-tetramethyl piperidine in 100 ml of toluene.
C18H28N42 (332-5) observed M~ 332 uanidine 6503 g of N-~-chlorobenzoyl-N~-[2,2,6,6-tetramethyl piperidinyl]-guanidine, a colourless powder melting at 130-134C &re obtained in the same way as in Example 8 from 3700 g of ~-chlorobenzoyl cyanamide and 31.5 g of 4-amino-2,2,6,6~tetramethyl piperidine in 100 ml of toluene.

Le A 16 859 - 26 -10'~521 C17H25ClN40 (336.9) observed M+ 336 N-Phenyl-N'-N"-bis-[2 2,6,6~tetrameth~ ridinyll-~uanidine 46.8 g of 4-amino-2,2,6,6-tetramethyl piperidine are dissolved in 100 ml of water, followed by the dropwise addition over a period of 3 hours of a solution of 17.4 g of phenyl isocyanide dichloride in 30 ml of dioxane. After stirring for another 2 hours at room temperature, the mixture is cooled to 0-5C, followed by the addition of a solution of 8 g of sodium hydroxide in 25 ml of water. The temperature of the mixture is allowed to rise to room temperature while stirring, and stirring is continued for another 2 hours at 50C. After cooling, the colourless product is filtered off under suction and dried. Yield 27 g9 mp 166-168Co C25H43N5 (413-7) observed M+ 413 Example 13 demonstrates the production of the substance described in Example 12 using a two-phase system.
62.4 g of 4-amino-2,2,6,6-tetramethyl piperidine are dissolved in 400 ml of lN sodium hydroxideO A solution of 34D8 g of phenyl isocyanide dichloride in 200 ml of methylene chloride is added dropwise with stirring to the solution at 40C. After stirring for another 3 hours at 40C, the mixture is left to oool, the organic phase is separated off and the solvent is evaporated off in vacuo. The solid left behind is washed with acetonitrile. Yield 71 g, mp 166-168C.

N-m-Nitrophenyl-N',N"-bis-[2,2,6,6-tetramethyl piperidinyl~-. . -~uanidine 39 g of 4-amino-2,2,6,6-tetramethyl piperdine are added to 100 ml of water and 10 g of sodium hydroxide are dissolved thereinO A solution of 7.4 g of m-nitrophenyl isocyanide Le A 16 859 ~ 27 -i~5~Zl dichloride in 60 ml of dioxane is added dropwise to the mixture over a period of 3 hours, followed by stirring for 1 hour at 60C. After cooling, the deep red coloured organic phase is separated off, the solvent is evaporated off in vacuo and the residue is left standing until it crystallises. The crystals formed are filtered under suction through a glass frit and washed twice with 25 ml of ether. Yield: 28.4 g of yellow crystals melting at 83-85C. The compound contains 1 mole of crystallised dioxane.
C25H42N62 (458.7) observed M~ 458 EXAMPLE 1~
N-Phenyl-N~-[2.2.6.6-tetramethyl piperidinyl]-guanidine 46.5 g of aniline are dissolved in 150 ml of tetra-hydrofuran and 15 g of cyanogen chloride are added dropwise to the resulting solution at 0C. After stirring for 15 minutes, the aniline hydrochloride precipitated is separated by filtration. 42.7 g of 4-amino-2,2,6,6,-tetramethyl piperidine are added dropwise to the filtrate at room temperature and the mixture is stirred for another 4 hours at room temperature. After filtration under suction and drying, 67 g of the compound are obtained in the form of a colourless powder melting at 146 to 148C. After recrystallisation from isopropanol, the substance has a melting point of 154C.
C16H26N4 (274.4) a) Procedure for Producin~ the polyurethane to be stabilised 1000 parts of an adipic acid/1,6-hexane diol/2,2-dimethyl-1,3-prQpane diol mixed polyester (molar ratio of the glycols 6~:35; molecular weight 1860) are mixed with Le A 16~ - 28 -l~SS;~i 1908 parts of N-methyl-bis-(~-hydroxypropyl)-amine, 28007 parts of diphenyl methane-4,4~-diigocyanate and 328 parts of dimethyl formamide, and the resulting mixture is heated for 72 minutes to 45-50C. After cooling to room temperature, the NCO-prepolymer formed has an NCO content of 2.92~ (based on solids).
748 parts of this prepolymer solution are introduced with stirring into a solution of 33.7 parts of H2N~NHoCO~NH~CH
CH2.CO.NH NH2 in 67 parts of water and 1570 parts of dimethyl formamide, The homogeneous viscous solution is pigmented with 4% of rutile9 based on the solids, and has a viscosity of 440 poises at 25C.
b) Measurement of the stabilisin~ effect usin~ elast_mer films and (cut) filaments The stabili-sers and comparison substances are added (in the form o.f a concentrated solution in dimethyl formamide) to the elastomer solutions in the quantities specified, followed by stirring for the purpose of homogenisation, after which the solutions are processed into the shaped articles.
The solutions are preferably coated onto glass plates in layer thicknesses of about 0.2 mm and dried in a drying cabinet at 70 to 100C to form films.
In a screening test the fi.lms are cut into approximately 1 cm wide strips and exposed to light in a Fadeometer (for assessment of discoloration and the qualitative behaviour of degradation on exposure to light).
The films are preferably cut in a film cutting machine into rectangular filaments with an overall denier of about 200 to 300 dtex and exposed to light in the form of these cut filamentsO On account of the large surface of the filaments, the damage cau~ed by the action of light is e ~ 16 859 - 29 -S~-21 more intensive and substantially equivalent to the behavlour of filaments spun on an industrial scale. The solutions can also be wet-spun or dry-spun.
c) Stabiliser additions and stabilisin~ effect The specified quantities of stabiliser are added to the polyurethane (urea) elastomer solutions a) 9 the solutions - are dried to form films and the films~ after cooling into300 dtex filaments, are exposed to light in a Fadeometer (cf.
Table) ~nd (in some cases) tested for tensile strength, elongation at break and discoloration (cf, Table l)o The elastomer solutions containing 2~ of stabiliser 1) are processed into elastomer filaments (approximately 300 dtex) both by the dry spinning process and by the wet spinning process. These filaments show substantially the same stabilisation to discoloration and approximately the same half lives of their tensile strength values after exposure to W -light as the filaments cut from films.
The stabilising additives have a distinot stabilising ,, ~
effect against deterioration of tensile strength, against reduction in elongation at break and, in particular, against discoloration under the effect of light.

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Le A 16 859 - 32 -ll)~SSZ~

The half lives of the tensile strength after exposure are considerably improved by the additions of sta~iliser (approximately 100~ to 200~ improvement from about 30 to about 90 Fadeometer hours~. The other elastic properties, such as elongation at break, modulus and permanent elongation, are retained much more satisfactorily. The surfaces of the polurethane films and coatings remain elastic on elongation, whereas in the case of the films with considerably reduced tensile strength they develop a crazed surface structure.
Another surprising aspect of the stabilising additives is their effectiveness when added in small quantities. Even when added in a quantity as small as 0.1%, a distinct initial stabilising effect is recognisable, although it is less active at higher light intensities. In quantities upwards of about -3%' however, the stabilising additives have a distinct stabilising effect which is improved relatively little in regard to discoloration by increasing the quantity added.
Combination with other types of antioxidants, for example phenolic types, affords certain advantages, although the influence of the stabilisers according to the invention generally predominates.
However, the particular effectiveness of the stabilisers i9 not confined solely to this tetramethyl piperidine radical.
Inst~ad it is decisively modified by the overall constitution of the stabiliser. This is illustrated in the comparison tests summarised in Table 3 where similar known compounds (cf. Table 2) have a very much wea~er effec$. The particular effectiveness of the stabilisers according to the invention could not be derived therefrom.

ke A 16 859 - 33 -1~9SS~

Table 2 Comparison Substances: According to F~l-PS 1, 360, 030 US-PS 3, 334, 103 A HO~CN FR-PS 1,526,656 H3C~t ~cCH33 B HN. CH . CH .CN according to 1 2 2 DT-OS 2,349,962 H3~<CH3 C H3C . N .CH2.CH2.CN according to 1 DT-OS 2, 349, 962 ~N/~

H

D H.N.H according to US-PS 3, 1 47, 268 ~ NL-OS 7, 313, 683 >l NJ<
H3C ~ CH3 The stabilising effects of these substances in the polyurethane according to Fxample 17 a) are shown in Table 3:

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Le A 16 859 _ 35 _ ~(~9~21 As the results show, there is little or no improvement in resistance to degradation or in reduction of discoloration in polyurethanes. ~he stabilishers according to the invention have a considerably better stabilising effect.
EXAMPLE ]7 a) Procedure for producin~ the_æolyurethan to be stabilised 718 parts of the NC0-prepolymer described in Example 10 are stirred into a carbamate suspension formed by adding 25 parts of solid carbon dioxide to a solution of 12.~8 parts of ethylene diamine (99%) in 1578 parts of dimethyl formamide. A highly viscous solution (visocisty approximately 210 poises) is obtained after pigmenting with 4% of rutile.
b) Stabilis n the pol~urethane accordin~ to 17 a) 2% 0 f each of the stabilisers according to Examples 1) and 4) are dissolved in portions of the solutions o~
Example 17 a) (ethylene diamine-extended polyester urethane) and, after processing into cut filaments (approximately 250 dtex), are compared with stabiliser-free filaments.
The lessstable polyurethane (by comparison with Example 16 a) is also improved by more than 100% in the half life of its tensile strength by addition of the stabilisers (from about 12 to about 30 Fadeometer hours).

600 parts of dimethyl terephthalate, 20 parts of dimethyl isophthalate and 980 parts of polytetramethylene glycol (molecular weight 980) are melted at about 150 to 165C with 750 parts of 1,4-butane diol. The resulting melt is mixed with 0.45 mMole of ~i(OC4Hg)4/(CH3C00)2.Mg and 0.05% by weight of di-~-naphthyl-p-phenylene diamine and the ester exchange reaction is carried out under Le A 16 859 - 36 ->52 IL

atmospheric pressure at 200 to 220C until the elimination of methanol is over. The temperature is then increased to 250C, vacuum is applied to an increasing extent and the excess butane diol is distilled off from the mixture under a pressure of about 0.3 to 005 Torr. After a polycondensation time of about 75 minutes, the melt is discharged under nitrogen and cooled.
The segmented copolyester ether elastomer is dissolved in hot tetrachloroethane to form a 20% solution. The stabiliser is dissolved in portions of the solution in quantities of 2%~ based on solids, and the solution is dried to form films.
The films (approximately 0.2mm thick) are exposed -to UV light in a Fadeometer. Whereas the unstabilised film is lemon yellow in colour after an exposure time of 1320 minutes and has lost its elasticity, i.e. is brittle and breaks very easily, the film containing 2% of stabiliser according to Example 1 ic; almost colourless and has remained elastic. With longer exposure, the slight yellowing fades; the stabilised films only begin to turn brittle after an exposure time of about 2500 minutes.

A 12% solution of a copolyamide (produced by the polycondensation of 50 parts by weight of caprolactam, 35 parts by weight of 1,6-hexamethylene diammonium adipate and 20 parts by weight of 1,6-hexamethylene diammonium sebacate) in 85 parts by weight of methanol, 6 parts by weight of isopropanol, 4.5 parts by weight of isobutanol and 4.5 parts by weight of water, is dried to form 3o approximately 0.10 mm thick films a) without the addition of a stabiliser, or Le A 16 ~9 _ 37 _ :~09~;~2~

b) with 2% by weight of the stabiliser according to Example 3, followed by exposure to light for 300 hours in a Fadeometer Thereafter, the unstabilised copolya~ide a) is brittle and breaks when the fi]m is bent, whereas the stabilised film b) remains flexible.

400 parts of a polytetramethylene ether diol with a molecular weight of 1045 (POLYMEG 1000, a product of the Quaker Oats Company) are reacted at 50C with a solution of 140.8 parts of diphenyl methane-4,4~-diisocyanate and 135 parts of dimethyl formamide until the N~O content amounts to 3. 2% (based on the solids content of the prepolymer solution).

6.02 parts o~ hydrazine hydrate are dissolved in 898 parts of dimethyl formamide, the carbonate suspension of the hydra~ine is formed by the addition of 10 parts of solid carbon dioxide and the suspension thus formed is reacted by stirring in 430 parts of the aboqe NCO-prepolymer solution to form the segmented linear polyurethane. The homogeneous, viscous elastomer solution (51 poises/20C) is pigmented with a TiO2-suspension (4/0 of TiO2/rutile, based on elastomer solids).
The solution i8 cast into elastomer films both with and without (comparison test) additions of stabiliser.
The elastomer films thus produced are Fadeometer tested in the form of strips (for results, see Table 4).
The results show that the unstabilis~d polyether urethane yellows very quickly and has been degraded after only 22 hours in the Fadeometer (no more strength, surface of the film "crackles" under minimal elongation).

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~9~i-S21 EXA~IPLE 21 A copolymer of 60 parts by weight of acrylonitrile and 40 parts by wei.ght of vinyl chloride is dissolved in dimethyl formamide at 40C to form a 22% solution. Portions of the solution with and without additions of stabiliser are cast to form approximately 0.15 mm thick films, followed by Fadeometer-testing~
Even when the solution is dried into films (about 1 hour/1000), the unstabilised film turns pale brownish in colour, whereas the film containi.ng 2% by weight of stabiliser No. 1 is colourless. In addition to this heat-stabilising effect, the stabiliser also affords protection against W -light. After 1320 minutes' Fadeometer testing, the stabilised film has not discoloured, whereas the discoloration of the unstabilised film has increased~

4-Cyanamido-2 2~6,6-tetramethyl piperidine 156 g (1 mole) of 4-amino-2,2,6,6-tetramethyl piperidine are dissolved. in 500 ml of methylene chloride, 40 g (1 mole) of sodium hydroxide in 500 ml of water are introduced and 51 ml of cyanogen chloride are added. dropwise at 0 to 5C.
The mixture is then stirred until it reaches room temperature, after whioh 4-cyanamido-2,2,6,6-tetramethyl piperidine melting at 240C is filtered off in a yield of 166 g (corresponding to 91.5~ of the theoretical).
CloHlgN3 (181.3~observed M+ 181 4-(N-Methyl-N-cyano~-amino-2~2~6 ~
170 g (1 mole) of 4-N-methyl amino-2,2,6,6-t~tramethyl piperidine are dissolved in 500 ml of methylene chloride, 40 g (1 mole) of sodium hydroxide in 500 ml of water are introduced and 51 ml of cyanogen chloride are added dropwise ~e A 16 8~ ~ 40 -109~

at O to 5C. The mix-ture is then stirred until it reaches room temperature. Thereafter, the organic phase is separated off, dried over sodium sulphate, filtered and the methylene chloride is distilled off, leaving as a residue 162 g (83% of the theoretical) of 4~(N-methyl-N-cyano)-amino-2,2,6,6-tetramethyl piperidine melting at 73 to 77C.
11 21N3 (195.3) observed M+ 195 4-(N-cyclohexyl-N-cyano)-amino 2, 2,6,6-tetramethyl piperidine melting at 123C is obtained in the same way as in Example 2 using 4-cyclohexyl amino-2,2,6,6-tetramethyl piperidine.
16H29N3 (263.4) observed M+ 263 4-(N-Benzyl-N-cyano)-amino-2,2,6,6-tetramethyl piperidine melting at 215-219C is obtained in the same way as in Example 2 using 4-benzyl amino-2, 2,6,6-tetramethyl piperidine.
C17H25N3 (271.4) observed M+ 271 Le A 16 85~ - 41

Claims (13)

1. Piperidinyl guanidine compounds corresponding to the general formula (I):

(I) and the corresponding tautomeric forms thereof, in which X represents a radical:

in which A represents hydrogen, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, an alkenyl or alkinyl radical having 3 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or the group -CH2-CHR4-OH, where R4 represents H, methyl or phenyl, R1 and R2 are the same or different and each represents a straight-chain or branched alkyl radical having 1 to 12 carbon atoms or R1 and R2, together with the ring carbon atom to which they are attached, form a cyclo alkyl ring having 5 to 12 carbon atoms, R3 represents hydrogen, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cyclo-alkyl radical having 5 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms, a .beta.-cyanoethyl Le A 16 859 - 42 -radical, a .beta.-alkoxy carbonyl ethyl radical having 1 to 3 carbon atoms in the alkoxy moiety, an aryl radical having 6 to 14 carbon atoms, the group -CH2-CHR4-OH, where R4 represents H,methyl or phenyl, or the group:

in which A, R1 and R2 are as defined above, Z has the same meaning as X or represents a group -NUV, where U and V are the same or different and each represents H, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may be substituted by alkyl radical having 1 to 8 carbon atoms and by C1-C4 alkoxy, hydroxy or nitro groups or by chlorine or bromine atoms, and in addition the radical U may represent a group R5-W, where R5 represents an aryl radical having 6 or 10 ring carbon atoms optionally substituted by chlorine, bromine, methyl or methoxy groups, a straight-chain or branched alkyl radical having 1 to 8 carbon atoms or an aralkyl radical having 7 to 12 carbon atoms, and W represents a CO- or SO2-group, the radical Y represents a group of the general formula =N-R6, where R6 represents H, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 7 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms Le A 16 859 - 43 -which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms and by C1-C4 alkoxy, hydroxy or nitro groups or by chlorine or bromine atoms, R3, R6, U and V not all being hydrogen at the same time.

2. Piperidinyl guanidine compounds of the general formula (I) in Claim 1, in which the radicals R1 and R2 are the same or different and represent alkyl radicals having 1 to 4 carbon atoms or together form a cyclohexyl ring, A represents H or an alkyl radical having 1 to 4 carbon atoms, R3 represents H, an alkyl radical having 1 to 8 carbon atoms, cyclohexyl, methyl cyclohexyl, benzyl, .beta.-cyanoethyl, 2-methoxy carbonyl ethyl or hydroxy ethyl, U and V are the same or different and represent H, alkyl radicals having 3 to 8 carbon atoms, cyclohexyl, benzyl or aryl, R5 represents phenyl,chlorophenyl, bromophenyl, tolyl, methoxyphenyl, naphthyl or benzyl, W represents a carbonyl group, and R6 represents H, alkyl radicals having 3 to 12 carbon atoms, cyclohexyl, phenyl, naphthyl, tolyl, chlorophenyl or nitro-phenyl, R3, R6, U and V not all representing hydrogen at the same time.

3. Piperidinyl guanidine compounds corresponding to the general formula (I) in Claim 1, in which the radicals R1 and R2 represent methyl, A represents H or methyl, R3 represents H, methyl, cyclohexyl, benzyl, .beta.-cyanoethyl or .beta.-hydroxy ethyl, U and V are the same or different and represent propyl, isopropyl, butyl, isobutyl, tert.-butyl, hexyl, cyclohexyl, Le A 16 859 - 44 -phenyl, tolyl, tert.-butyl phenyl, chlorophenyl or naphthyl, R5 represents phenyl, chlorophenyl, tolyl or methoxy phenyl, and R6 represents H, phenyl, chlorophenyl, nitrophenyl or naphthyl.

4. A process for the preparation of piperidinyl quanidine compounds corresponding to the general formula (I) as claimed in claim 1 and the corresponding tautomeric forns thereof which comprises:
(a) where a compound of formula (I) is desired wherein Z has the same meaning as X and R6 is not hydrogen, reacting a 4-aminopiperidine compound corresponding to the formula (IV):

(IV) (wherein R1, R2, R3 and Aare as defined in claim 1) with an isocyanide di-chloride corresponding to the formula (V):

(V) (wherein R7 has the same meaning as R6 as defined in claim 1 except for hydro-gen) at temperatures in the range of from -10°C to 100°C in the presence of solvents, from 2 to 4 moles of the 4-amino-piperidine of formula (IV) being used per mole of tlne isocyanide dichloride of formula (V), whereby there is obtained a piperidinyl guanidine corresponding to the general formula (VI):

(VI) (wherein A, R1, R2, R3 and R7 are as defined above);

(b) where a compound of formula (I) is desired wherein R3 is hydrogen, R6 is not hydrogen and Z is -NUV wherein U is hydrogen and V is not hydrogen nor an aralkyl radical having 8 to 12 carbon atoms, reacting a 4-aminopiperidine corresponding to the formula (VII):

(VII) (wherein R1, R2 and A are as defined in claim 1) with a carbodiimide correspond-ing to the formula (VIII):

R8 - N = C = N - R9 (VIII) (wherein R8 and R9 have the same meaning as R6 as defined in claim 1 except for hydrogen) at temperatures in the range of from 20 to 200°C whereby there is obtained a piperidinyl guanidine corresponding to the general formula (IX):

(IX) (wherein A, R1, R2, R8 and R9 are as defined above);

(c) where a compound of formula (I) is desired wherein R6 is hydrogen and Z is -NUV wherein U and V are not C2-4 aIkoxy- nor hydroxy-subgtituted aryl radicals, reacting a 4-aminopiperidine corresponding to the formula (XI):

(XI) (wherein R1, R2, R3 and A are as defined in claim 1) with a cyanamide cor-responding to the formula (XII):

(XII) (wherein R10 and R11 are the same or different and represent H, a straight-chain or branched aIkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms, methoxy, nitro, chlorine or bromine atoms, or R10 represents the group R5-W where R5 and W
are as defined in claim 1) in an organic solvent at temperatures in the range of from -10 to +100°C, from 0.5 to 8 moles of the 4-aminopiperidine of formula (XI) being used per mole of the cyanamide of formula (XII), where-by there is obtained a piperidinyl guanidine corresponding to the general formula (XIII):

(XIII) (wherein A, R1, R2, R10 and R11 are as defined above), or (d) where a compound of formula (I) is desired wherein R6 is hydrogen and Z is -NUV wherein U and V are not C2-4 alkoxy- nor hydroxy-substituted aryl radicals and U is not R5-W, reacting a cyanamide correspond-ing to the formula (XIV):

(XIV) (wherein R1, R2, R3 and A are as defined in claim 1) with an amine correspond-ing to the formula (XV):

(XV) (wherein R11 and R12 are the same or different and represent H, a straight-chain or branched alkyl radical having 1 to 20 carbon atoms, a cycloalkyl radical having 5 to 12 carbon atoms, an aralkyl radical having 7 to 12 carbon atoms or an aryl radical having 6 to 14 carbon atoms which may in turn be substituted by alkyl radicals having 1 to 8 carbon atoms, methoxy, nitro, chlorine or bromine atoms) in an organic solvent at temperatures of from -10 to +100°C, from 0.5 to 8 moles of the amine of formula (XV) being used per mole of the cyanamide of formula (XIV), whereby there is obtained a piperidi-nyl guanidine corresponding to the general formula (XIII):

(XIII) (wherein A, R1, R2, R3, R11 and R12 are as defined above).

5. A process as claimed in claim 4(a), wherein from 2 to 3 moles of the 4-aminopiperidine of formula (IV) are used per mole of the isocyanide dichlo-ride of formula (V).

6. A process as claimed in claim 4(a), wherein 2 moles of the 4-amînopiperidine of formula(IV) are used per mole of the isocyanide dichloride of formula (V).

7. A process as claimed in claim 4(b) wherein from 1 to 1.5 moles of the 4-aminopiperidine of formula (VII) are used per mole of the carbodi-imide of formula (VII).

8. A process as claimed in claim 4(b) wherein from 1 to 1.1 moles of the 4-aminopiperidine of formula (VII) are used per mole of the carbodi-imide of formula (VIII).

9. A process as claimed in claim 4(c), wherein from 0.9 to 1.5 moles of the aminopiperidine of formula (XI) are used per rnol of the cyanamide of formula (XII).

10. A process as claimed in claim 4(c), wherein from 1 to 1.2 moles of the 4-aminopiperidine of formula (XI) are used per mol of the cyanamide of formula (XII).

11. A process as claimed in claim 4(d), wherein from 0.9 to 1.5 moles of the amine of formula (XV) are used per mole of the cyanamide of formula (XIV).

12. A process as claimed in claim 4(d), wherein from 1 to 1.2 moles of the amine of formula (XV) are used per mole of the cyanamide of formula (XIV).

13. A method for stabilizing a synthetic polymer which comprises adding to said polymer a piperidinyl guanidine as claimed in claims 1 to 3 in effective amounts.