GB2319393A - Use of a 1-propyl-4-dialkyl benzene compound as an inhibitor of the formation of free radicals - Google Patents
Use of a 1-propyl-4-dialkyl benzene compound as an inhibitor of the formation of free radicals Download PDFInfo
- Publication number
- GB2319393A GB2319393A GB9722186A GB9722186A GB2319393A GB 2319393 A GB2319393 A GB 2319393A GB 9722186 A GB9722186 A GB 9722186A GB 9722186 A GB9722186 A GB 9722186A GB 2319393 A GB2319393 A GB 2319393A
- Authority
- GB
- United Kingdom
- Prior art keywords
- formula
- compound
- solvent
- isopropyl
- benzene
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C15/00—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
- C07C15/02—Monocyclic hydrocarbons
- C07C15/107—Monocyclic hydrocarbons having saturated side-chain containing at least six carbon atoms, e.g. detergent alkylates
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C15/00—Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
- C07C15/02—Monocyclic hydrocarbons
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
- G21C19/42—Reprocessing of irradiated fuel
- G21C19/44—Reprocessing of irradiated fuel of irradiated solid fuel
- G21C19/46—Aqueous processes, e.g. by using organic extraction means, including the regeneration of these means
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for the reprocessing of nuclear fuels uses a solvent-diluent system for extracting the uranium and/or plutonium, in which the diluent is a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I): in which R 1 is an alkyl group of formula C n H 2n+1 , R 2 is an alkyl group of formula C m H 2m+1 and m and n are integers such that 3 * less than or equal to * m+n * less than or equal to * 13. The invention also relates to a process for reprocessing nuclear fuels using a solvent-diluent system for extracting uranium and/or plutonium and to a process for preventing the degradation by radiolysis of a liquid or gaseous medium using a compound (I).
Description
USE OF A 1-ISOPROPYL-4-DIALKYL METHYL BENZENE COMPOUND
AS AN INHIBITOR OF THE FORMATION OF FREE RADICALS
DESCRIPTION
TECHNICAL FIELD
The present invention relates to the use of 1-isopropyl-4-dialkyl methyl benzene compounds as inhibitors of the formation of free radicals.
The invention also relates to the use of 1-isopropyl-4-dialkyl methyl benzenes as diluents-inhibitors, i.e. as diluents on the one hand and as inhibitors of the formation of free radicals on the other, more especially in processes for the reprocessing of irradiated nuclear fuels.
In the case of processes for the reprocessing of nuclear fuels (PUREX process), use is made of a solvent-diluent system, i.e. a system comprising a solvent and a diluent, for the liquid-liquid extraction of uranium and/or plutonium. The most widely used solvent is tributyl phosphate (TBP) and the most widely used diluent is a petroleum fraction, i.e. a fraction of saturated hydrocarbons comprising carbon chains with 4 to 14 carbons, which are liquid at ambient temperature, of low viscosity and having the advantage of being easily regeneratable. This solvent-diluent system is used as the complexing agent for extracting uranium and/or plutonium from an aqueous acid solution such as an irradiated fuel dissolving solution.
As a result of an intense radiolysis due to uranium, plutonium and certain fission products, said system is subject to degradation, which is prejudicial to the quality of the solvent.
Thus, in the solvent-diluent system during the extraction process is observed a reduction in the titre of the tributyl phosphate, a loss of selectivity with respect to the plutonium and/or uranium, as well as the obtaining of troublesome derivatives potentially complexing lanthanides and actinides.
The formation of these troublesome derivatives is governed by the creation of different radicals, e.g. the TBP radical when the solvent is tributyl phosphate, which lead to the formation of diluent
TBP covalent adducts or dimers.
The radiolysis of the solvent TBP also contributes to the formation of dibutyl phosphoric acid (DBP), but what is more serious is that said radiolysis also produces very varied compounds by grafting radicals on molecules of diluent thus giving a very complex mixture e.g. comprising carboxylic acids, butanol, dodecanol, carbonyl derivatives, nitro derivatives and unidentified, polyfunctional products.
Certain of these polyfunctional products have powerful complexing properties, which could explain an increasing retention during the extraction process in the solvent of radioactive elements such as o6
Ru, zirconium and plutonium.
Among these derivatives, the most disturbing and largest as regards weight is dibutyl phosphoric acid (DBP), whose accumulation in extraction cycles creates significant difficulties. These difficulties are: - a strong complexing of the plutonium in the solvent phase, which
slows down its transfer to the aqueous phase during reextraction
operations, - a lowering of the surface tension of the solvent, which is
unfavourable to the coalescence of emulsions and the liberation
of phases in settling/decanting tanks, - a formation of only very slightly soluble precipitates with:
zirconium, forming interface dirt accentuating the radiolysis
of the solvent,
plutonium, giving rise to blockages and dangerous accumula
tions of fissile material and
corrosion iron which, like plutonium dibutyl phosphate, dirties
equipment and trays of pulsed columns.
All these chemical modifications of the solvent give rise to changes to the physical properties of the solvent, i.e. changes to its density, its viscosity and its coalescence time of emulsions and its surface tension.
Therefore the solvent must be treated before being recycled, in order to limit the proliferation of such waste and polyfunctional products and in order to restore its chemical and physical properties. In other words, it is necessary to eliminate the radioactive products and degradation products which have accumulated there and which are harmful to the satisfactory operation of the extractions.
The solution presently used for eliminating the derivatives created by radiolysis of the solvent is a distillation of the organic phase at the end of the extraction treatment. This method is effective, but requires large, costly equipment.
DESCRIPTION OF THE INVENTION
The present invention specifically aims at supplying a process for the reprocessing of nuclear fuels using a solvent-diluent system for extracting the uranium and/or plutonium, in which the diluent is a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I):
in which R1 is an alkyl group of formula CnH2n+1, R2 is an alkyl
n group of formula C H2m+ i, and m and n are integers such that
m 3 < m+n < 13.
R and R
The R and R alkyl groups are straight or branched.
In particular, the alkyl group R of the compound of formula (I) according to the invention is a methyl or pentyl group, and the alkyl group R is a butyl or pentyl group.
As an example of compounds of this type reference can be made to 1-isopropyl-4-(6-undecanyl)-benzene, 1-isopropyl-4-(2-heptanyl)benzene and 1-isopropyl-4-(2-hexanyl)-benzene.
The invention also relates to a process for reprocessing nuclear fuels using a solvent-diluent system for extracting uranium and/or plutonium, in which the solvent-diluent system also contains an inhibitor of the formation of free radicals constituted by a compound (I), as defined hereinbefore.
The compound (I) of the present invention has a particular structure giving it the property of easily supplying a large number of free radicals under radiolysis.
Thus, the carbon linking the isopropyl in the 1-position of the benzene cycle and the carbon linking the dialkyl methyl in the 4position of the benzene cycle are tertiary carbons giving free radicals H under radiolysis, in accordance with the reaction:
\ / H3C CN3 C CH3 C + iLUIDLY'IC ; 2h C.
/\ / \ ~ Rl R9 Rl R2 (!) (it) The presence of these two tertiary carbons activated by the benzene nucleus stabilizes by resonance the free radical (Ia) formed and guarantees a good yield of formation of free radicals H'.
As these free radicals H are small and penetrating and in large numbers due to the stabilizing structure of compound (I) according to the invention, they make it possible to regenerate and/or prevent the formation of less stable free radicals emanating from other compounds, in a liquid or gaseous medium, under radiolysis.
The compound according to the invention can e.g. be used in processes for the extraction of plutonium and/or uranium using a solvent-diluent system incorporating TBP.
Thus, in such processes use is made of a solvent-diluent system in which the solvent is tributyl phosphate (TBP) and the diluent is a petroleum fraction. As a result of the intense radiolysis, the TBP easily degrades giving rise to the formation of harmful derivatives through the creation of different radicals TBP-.
Compound (I) according to the invention produces easily and in large numbers free radicals H under radiolysis and as a result of the considerabie stability of compound (Ia) in radical form, which is superior to that of the radical TBP , the free radicals H make it possible to regenerate the solvent by linking with the free radicals TBP.
Thus, compound (I) is very interesting as an inhibitor of the formation of free radicals in a liquid or gaseous medium for preventing the degradation of said medium by radiolysis.
The invention also relates to 2 process for preventing the degradation by radiolysis of a liquid or gaseous medium consisting of adding to said medium a compound (I), as described hereinbefore.
In addition1 compound (I), as a result of its structure, has the characteristics of a good diluent, i.e. it is liquid at ambient temperature, has a low viscosity and is easily regeneratable. Consequently compound (I) has properties identical to those of petroleum fractions, such as saturated hydrocarbon fractions, e.g. with 4 to 14 carbon atoms.
Thus, compound (I) according to the invention, not only has the characteristics of an effective inhibitor of the formation of free radicals, in the liquid or vapour phase, but it can also replace the diluent in the solvent-diluent system for the extraction of plutonium and/or uranium in fuel reprocessing processes.
Another advantage of compound (I) according to the invention is that it can easily be recycled. It can be recycled either directly, when a single radical hydrogen has been surrendered, by recombination with a radical H of the solution, or indirectly, when two radical hydrogens have been surrendered (the compound is dearomatized) by oxidation, e.g. by blowing a little air into the solution.
Thus, compound (I) can e.g. be used in particularly interesting manner in processes for the reprocessing of spent nuclear fuels.
Preferably, in the solvent-diluent system, when the solvent is tributyl phosphate (TBP) and when the diluent is a compound (I) according to the invention, the solvent/diluent volume ratio is 25 to 65X.
When compound (I) is used solely as an inhibitor, it can be added to the reaction medium at a rate of 0.5 to 70% by weight of the solventdiluent system, particularly 0.5 to 5 by weight of the solventdiluent system.
The use of compound (I) according to the invention is particularly interesting when the solvent is tributyl phosphate (TBP).
It is obvious that the compound of formula (I) according to the invention can be used in the form of a single compound of formula (I) or in the form of a mixture of several compounds of formula (I), in the form of a pure isomer or in racemic form.
A process for the preparation of a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I):
in which R and R are as defined hereinbefore, can consist of reducing a tertiary alcohol (II) of formula:
in which R and R are as defined hereinbefore, in order to obtain the aforementioned compound (I).
The reduction of the tertiary alcohol (II) takes place by conventional processes, which are known in the art, for the reduction of a tertiary alcohol. For example, said reduction can take place in the presence of triethyl silane and trifluoroacetic acid under a neutral atmosphere and at ambient temperature.
The compound (I) formed is extracted from the reaction medium and washed by known processes in connection with this type of extraction and washing. For example, compound (I) is extracted with the aid of a saturated sodium hydrogen carbonate solution and washed with the aid of a sodium chloride solution.
When in the tertiary alcohol of formula (II) the alkyl groups R and are identical, e.g. when R and R are both pentyl groups, it is possible to prepare said tertiary alcohol by performing the following stages: a) reacting para-isopropyl benzoic acid of formula (II):
with an alcohol of formula R -OH, in which R is an alkyl group with 2 to 5 carbon atoms, in order to obtain an ester of formula (IV):
b) reacting the ester of formula (IV) with an organometallic com
1 1 pound of formula R -MX, R being as defined hereinbefore, M being a metal chosen from among Cd and Mg, and X being a halogen chosen from among Br, Cl and I in order to obtain a mixed metal alkoxide, c) hydrolyzing the mixed metal alkoxide obtained previously in order to obtain the tertiary alcohol of formula (II):
in which R2=R1.
Stage a) corresponds to an esterification between the para-isopropyl benzoic acid and the alcohol R3-OH. Esterification takes place under appropriate, known conditions for obtaining a good quantity of ester. For example, it can take place in an acid medium by adding catalytic quantities of H2SO, hot and under reflux for one night.
The crude esterification product is washed, e.g. with a saturated sodium carbonate solution and then with a saturated sodium chloride solution. The ester of formula (IV) obtained is dried, filtered and concentrated by known methods.
In stage b), the ester of formula (IV) is reacted with an organometallic compound of formula R MX to obtain a mixed metal alkoxide.
The organometallic compound preferred according to the invention is n-pentyl-bromomagnesium, C5H1OMgBr, M being magnesium, X being bromine and R a pentyl group. It is a question of reacting an organometallic compound with an ester, i.e. a nucleophilic auction.
This reaction is commonly called the Grignard reaction with a reverse addition to alkyl para-isopropyl benzoate.
In this reaction, following a normal stage of adding the organometallic compound R1-MX to the ester of formula (IV), a metal alkoxide molecule R3 -OMX is eliminated forming a ketone of formula (V):
This ketone of formula (V) in turn reacts with R -MX to give the mixed metal alkoxide.
This Grignard reaction is performed under well known conditions, i.e. cold and in a strictly dry environment. This gives a mixed metal alkoxide.
In stage c), the mixed metal alkoxide formed is hydrolyzed to obtain the tertiary alcohol of formula (II).
Hydrolysis takes place under known conditions for the hydrolysis of alcohols, e.g. with a saturated NH4Cl solution. The tertiary alcohol obtained is extracted by known methods for extracting an alcohol, e.g. using ether, and the product obtained is then dried, e.g. on MgS04.
When the organometallic compound used is n-pentyi-bromornagnesium, the tertiary alcohol (II) obtained is l-isopropyl-4-(6-undecanyl-6- ol)-benzene.
When in the tertiary alcohol of formula (II) the alkyl groups R1
2 and R are different, said tertiary alcohol can be prepared by performing the following stages: a) reacting a compound of formula (V):
in which R1 is as defined hereinbefore, with an organometallic compound of formula R2-ftX, in which R2 is as defined hereinbefore, M is a metal chosen from among Cd and Mg, and X is a halogen chosen from among Br, C1 and I, in order to obtain a mixed metal alkoxide, b) hydrolyzing the mixed metal alkoxide obtained previously to obtain the tertiary alcohol of formula (II):
In compound (V), the alkyl group R is as defined hereinbefore and is preferably a methyl or pentyl group.
This compound is an alkyl(4-isopropyl phenyl)-ketone, which is commercially available, or which can be prepared by known procedures.
In this process, the preferred organometallic compound is an organo 2 magnesium compound, M being magnesium, X bromine and R as defined
2 hereinbefore, e.g. R is a pentyl or butyl group.
Stage a) of the process is a Grignard reaction, as defined and described hereinbefore, and makes it possible to obtain a mixed metal alkoxide.
In stage b), the mixed metal alkoxide obtained is hydrolyzed under known conditions for the hydrolysis of alcohols, e.g. with a saturated NH4Cl solution, in order to obtain the tertiary alcohol of formula (II) with R1 and R2 being different.
When R is a methyl group and R2 a pentyl group, the tertiary alkoxide (II) obtained is 1-isopropyl-4-(2-heptanyl-2-ol)-benzene.
When the group R is a methyl group and R is a butyl group, the tertiary alcohol (II) obtained is l-isopropyl-4-(2-hexanyl-2-ol)- benzene.
Other features and advantages of the invention can be better gathered from reading the following description and examples given in a purely illustrative and non-limitative manner.
Example 1: Preparation of 1-isopropel-4-(6-undecanvl)-benzene of formula (1):
This compound formula (1) corresponds to the compound of formula (I) according to the invention, in which R1 is a C5H1l alkyl group and R2 is identical to R1.
The preparation of the compound of formula (1) comprises the preparation of a tertiary alcohol of formula (2):
from para-iospropyl benzoic acid, followed by the reduction of said tertiary alcohol of formula (2) in order to obtain the compound of formula (1):
Preparation of the tertiary alcohol of formula (2):
This preparation comprises two stages, the first stage being an esterification reaction between ethanol and para-isopropyl benzoic acid in order to form an ester of formula (2'):
3 corresponding to the compound of formula (IV), in which R is an ethyl group. The second stage is a Grignard reaction on said ester of formula (2') in order to form the alcohol of formula (2).
Esterification takes place by mixing in a flask one equivalent of paral-isopropyl benzoic acid, six equivalents of ethanol and a few drops of concentrated sulphuric acid. The mixture is refluxed for one night in order to obtain a crude esterification product in an organic phase. The crude product formed is washed twice with a saturated sodium carbonate solution and then once with a saturated sodium chloride solution. The washing solutions (sodium carbonate and sodium chloride) are treated twice with dichloromethane in order to extract therefrom the organic phase residues. The organic phases are collected, dried on MgS04, filtered and concentrated with the rotary evaporator. The ester of formula (2') obtained is in the form of a pink oil. The yield of the reaction is 86%.
The characteristics of the ester of formula (2') obtained are given in the following table 1:
TABLE 1 1H NMR ippm 8 (d, t; 2H; aromatic) (250 MHz/CDC13) 7.31 (d, t, 2H; aromatic)
4.4 (q; 2H; J=7.5 Hz)
2.99 (hept.; 1H; J=7.5 H2) 1.42 (t; 3H; J=7.5 Hz)
3
1.3 (d; 6H; J=6.75 Hz) 13C NMR tppp 166.7; 154.2; 130.37; (62.9 MHz/CDC13) 129.73; 128.21; 126.42;
60.72; 34.27; 23.72;
14.38.
This is followed by a Grignard reaction on the ester of the paraisopropyl benzoic acid and ethanol. The organometallic compound used is n-pentyl bromomagnesium of formula C5 H 11MgBr.
In a three-necked flask, surmounted by a condenser and a dropping funnel, strictly dry and under argon, are placed 2.2 equivalents of n-pentyl bromomagnesium, i.e. 9.8 mmole, diluted in 10 ml of ether anhydride. The three-necked flask is cooled to O"C, then one equivalent of the previously formed ester, i.e. 4.16 mmole, diluted in 10 ml of anhydrous ether, is added dropwise. Stirring takes place for one hour at O4C and then 2 hours under reflux of the ether in order to obtain a mixed metal alkoxide.
Thin layer chromatographic analysis made it possible to determine the end of the reaction. The mixed metal alkoxide formed has the same RF (front reference) as the ester. However, the alkoxide is revealed by Vagi, whereas the ester is revealed by UV.
The KAgI (potassium silver iodide) is a developer of spots used in thin film chromatography. This developer makes it possible to differentiate the products not revealed in UV. The mixed metal alkoxide is then hydrolyzed with a saturated NH4Cl solution for one hour.
The reaction medium is taken up with a little ether, filtered on celite and the precipitate obtained is rinsed several times with ether. The aqueous phase is treated with ether in order to extract therefrom the organic residues. The ethereal phases are collected, dried on MgS04, filtered and concentrated. The product obtained is in the form of a yellowish oil. 930 mg of alcohol are obtained and the reaction yield is 77%. The desired product is in the majority, but it contains small amounts of dehydration products, such as two olefins at m/z=272.
The characteristics of the product obtained are given in the following table 2:
TABLE 2 1H NMR Sppm 7.4-7.1 (d, d; 4H) 3 (250 MHz/CDC13) 2.89 (hept.; 1H; J=6.75 Hz) 1.9-1.7 (m; 5H)
1.4-1.1 (m; 18H)
1-0.7 (m, 6H)
GC-MS m/z 273 (M-OH), 219 (M-C5H1l), 177, (IE/70 eV) 147, 118, 100, 72
The tertiary alcohol of formula (2) formed is then reduced to obtain the compound of formula (1).
Reduction of the tertiary alcohol of formula (2):
In a flask is placed one equivalent of the alcohol of formula (2) diluted to 0.2 M in a distilled dichloromethane solution, under an argon atmosphere. This is followed by the addition of 1.1 equivalent of triethyl silane and then 3 equivalents of trifluoroacetic acid in order to obtain a reaction mixture.
The reaction mixture darkens instantaneously as from the addition of the trifluoroacetic acid and a slight heating is observed.
Stirring takes place at ambient temperature for one night and then the reaction medium is poured into 100 ml of saturated sodium hydrogen carbon solution. Two phases form, namely an aqueous phase and an organic phase. The organic phase contains the esterification reaction product, i.e. the compound of formula (1). The organic phase is decanted and washed with a saturated sodium chloride solution. The aqueous phase is treated three times with dichloromethane in order to extract therefrom the organic phase residues.
The organic phases obtained are collected, dried on gS04, filtered and concentrated to give a product in the form of an orange-yellow oil, which is the compound of formula (1). The compound of formula (1) is purified by flash chromatography on silica using cyclohexane as the eluent. This gives a colourless oil of the compound of formula (1), with a reaction yield on silica, eluting with cyclohexane. A colourless oil is obtained. The yield of this reaction is 87 to 89%.
Secondary products are formed, these being substitution products of a C5HIl chain by a hydrogen at m/z=204, or products at m/z=234.
The characteristics of this product are given in the following table 3:
TABLE 3
H NMR sppm 7.12-7.03 (d, d; 4H; aromatics) (250 MHz/CDCl3) 2.87 (hept; lH; J=7 Hz)
2.41 (m; 1H) 1.7-1.4 (m; 4H)
1.35-1 Cm; 18H) 3
0.82 (t; 6H; J=6.25 Hz) 13C NMR appm 145.95; 143.76; 127.43; (62.9 MHz/CDC13) 126.08; 45.58; 36.91; 33.61;
32.05; 27.35; 24.05; 22.59; 14.1 -1
IR V 2957, 2926, 2856, 1510,
cm (liquid film) 1465, 1379, 1363, 827, 727
GC-MS* m/z 274 (M+), 203, 161, 133, (IE/70eV) 121,119, 105, 91 * (gas chromatography and mass spectrometry)
Example 2: Preparation of 1-isopropyl-4-(2-heptanyl)-benzene of formula (3):
corresponding to the compound of formula (I), in which R1 is a
2 methyl group and R is a pentyl group.
The preparation of the compound of formula (3) comprises the preparation of a tertiary alcohol of formula (4):
corresponding to the compound of formula (II), in which R1 and R2 are as defined hereinbefore, from 4-isopropyl acetophenone of formula (7):
followed by the reduction of said tertiary alcohol of formula (4) to obtain the compound of formula (3).
Preparation of the tertiary alcohol of formula (4):
This preparation takes place by a Grignard reaction.
In a three-necked flask, surmounted by a condenser and a dropping funnel, strictly dry and under argon, is placed 1.2 equivalent of n-pentyl magnesium bromide, of formula C5H1lMgBr, diluted to 0.05 M in an anhydrous ether solution. The three-necked flask is cooled to O"C, followed by the addition of one equivalent of 4-isopropyl acetophenone of formula (7), diluted to 1 M in an anhydrous ether solution in dropwise manner. Stirring takes place for one hour at O"C and then two hours under reflux of the ether. This is followed by the hydrolysis of the reaction product with a saturated ammonium chloride solution, followed by stirring for one hour. The reaction medium is taken up with a little ether, filtered on celite and the precipitate is rinsed several times with ether.
The aqueous phase is extracted with ether. The ethereal phases are dried on MgSO4, filtered and concentrated. This gives a clear yellow oil, where the alcohol of formula (4) is in the majority, but, as in example 2, it contains very small amounts of dehydration products (two olefins at m/z=216). The yield of this reaction is %.
872.
The characteristics of the product formed are given in the following table 4:
TABLE 4 1 NMR 6 ppm 7.35-7.19 (d, d; 4H) (250 MHz/CDCl3) 2.89 (hept.; 1H; J=6.9 Hz)
1.85-1.7 (m; 2H)
1.69 (s; 0H; exchangeable D20)
1.52 (s; 3H) 1.3-1.1 (m; 14H)
3
0.85 (t, 3H; J-6.8 Hz) 13C NMR ppm 146.93; 145.56; 126.53; (62.9 MHz/CDCl3) 126.11; 125.45; 124.73; 74.59;
44.15; 33.62; 32.48; 32.21;
29.92; 23.99; 23.71; 22.57;
14.05
GC-MS m/z 233 (M-H20+CH5+), 217 (M+H-H20), (Cl/methane) 163; 147
The tertiary alcohol of formula (4) formed is then reduced to obtain the compound of formula (3).
Reduction of the tertiary alcohol of formula (3):
This reduction takes place in accordance with the operating procedure described in example 1. l-isopropyl-4-(2-heptanyl)-4 benzene is obtained with an 89 yield.
A minute quantity of a product at m/z=204 is observed, together with residues in a quantity lower than 3X of the starting alcohol, at m/z=234, which has not reacted.
During a reaction performed on several grams of alcohol of formula (4) of concentration 3 M in dichloromethane, there is also a formation of dimers of respective mass m/z 378, 432 and 434. These dimers can be eliminated either by distillation, or by chromatography. Their formation can be reduced by working in a more dilute medium.
The characteristics of the compound of formula (3) formed are given in table 5.
TABLE 5 1H NMR Eppm 7.2-7 (d, d; 4H; aromatics) (250 MHz/CDCl3) 2.87 (hept.; 1H; J=7 Hz) 3
2.6 (sext; 1H; J=7 Hz) 1.6-1.45 (m; 2H)
1.35-1.1 (m; 15H) 0.85 (t; 3H; J=6.5 Hz) 130 NMR Eppm 146.08; 145.34; 126.81; (62.9 MHz/CDC13) 126.23; 39.46; 38.52; 33.64;
32.0; 27.44; 24.06; 22.61;
22.23; 14.1 IR V -1 2958, 2926, 2870, 1508,
cm (liquid film) 1459, 1376, 1363, 827, 727
GC-MS m/z 218 (M ), 203, 175, 161, (IE/70 eV) 147, 133, 119, 105, 91
Example 3: Preparation of 1-isopropyl-4-(2-hexanyl)-benzene of formula (5):
corresponding to the compound of formula (I) according to the invention, in which R1 is a methyl group and R2 a butyl group.
The preparation of the compound of formula (5) comprises the preparation of a tertiary alcohol of formula (6):
from 4-isopropyl acetophenone of formula (7):
followed by the reduction of said tertiary alcohol of formula (6) to obtain the compound of formula (5).
Preparation of the tertiary alcohol of formula (6):
This reaction is similar to that performed in example 3.
The Grignard reagent, i.e. the organometallic compound, is formed in situ by adding the n-butyl bromide to magnesium in filing form, in distilled ether. This gives n-butyl bromomagnesium of formula
C4H9MgBr. This reagent is then dosed by iodine and used directly in a three-necked flask, as in example 2. The operating procedure for the synthesis of this alcohol is the same as that given in example 2. The reaction yield is
Reduction of the tertiary alcohol of formula (6):
This reduction takes place in the presence of triethyl silane, trifluoroacetic acid, dichloromethane and at ambient temperature, in accordance with the same operating procedure as for examples 1 and 2. This gives 1-isopropyl-4-(2-hexanyl)-benzene with a 75X yield.
Small amounts of dimers are formed.
The characteristics of the product formed are given in table 7.
TABLE 7 1H NMR Eppm 7.4-7.1 (d, d; 4H) (250 MHz/CDCl3) 2.9 (m; 1H) 1.85-1.72 (m; 2H)
1.69 (s; OH; exchangeable D20)
1.55 (s; 3H)
1.3-1.1 (m; 10H) 3
0.85 (t, 3H; J=6.8 Hz) GC-MS m/z 220 (M ); 203 (M-OH); 163; (IE/70 eV) 148; 122; 106; 57
Example 4
In this example, an inhibitor/diluent (compound (1)) according to the invention was used under different concentrations as the inhibitor of the degradation of a solvent TBP.
The degradation of the solvent TBP was simulated by radiolysis, cobalt cylinder, mixtures containing TBP, nitric acid, TPH (petroleum fractions) and/or different inhibitor quantities.
In this example, as for nuclear fuel treatment processes, the proportion of TBP in the mixtures is 30% by weight and the proportion of TPH and/or inhibitor is 70X by weight.
The inhibiting effect of compound (I) according to the invention was evaluated by measuring the production of degradation products of
TBP by radiolysis. The reduction of certain radiolysis products, particularly TBP dimers, reached 50 to 60% compared with the same solution without inhibitor.
Claims (13)
1. Process for the reprocessing of nuclear fuels using a solventdiluent system for extracting uranium and/or plutonium, wherein the diluent is a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I):
in which R1 is an alkyl group of formula C H2 1 R is an alkyl
n group of formula C H and m and n are integers such that
m 2m 3 Cm+n 413.
2. Process for the reprocessing of nuclear fuels using a solventdiluent system for extracting uranium and/or plutonium, wherein the solvent-diluent system also comprises an inhibitor of the formation of free radicals constituted by a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I):
1 2 in which R is an alkyl group of formula C H 1 R is an alkyl
n 2n1 group of formula CmH2m+1, and m and n are integers such that
m 2m+1 3 m+n 13.
3. Process according to claim 1 or 2, wherein R is a methyl or pentyl group.
4. Process according to any one of the claims 1 to 3, wherein R2 is a butyl or pentyl group.
5. Process according to claim 1 or 2, wherein the compound is chosen from among 1-isopropyl-4-(6-undecanyl)-benzene, 1-isopropyl4-(2-heptanyl)-benzene, or 1-isopropyl-4-(2-hexanyl)-benzene.
6. Process for the processing of nuclear fuels according to any one of the claims 1 to 5, wherein the solvent is tributyl phosphate.
7. Process according to claim 1, wherein, in the solvent-diluent system, the solvent/diluent volume ratio is 25 to 604.
8. Process according to claim 2, wherein the inhibitor is added at a rate of 0.5 to 70% by weight of the solvent-diluent system.
9. Process according to claim 2, wherein the inhibitor is added at a rate of 0.5 to 5X by weight of the solvent-diluent system.
10. Process for preventing the degradation by radiolysis of a liquid or gaseous medium consisting of adding to said medium a 1-isopropyl-4-dialkyl methyl benzene compound of formula (I):
1 2 in which R is an alkyl group of formula C H 1' R is an alkyl
n 2n*1 group of formula CmH2n+1, and m and n are integers such that 3 m+n 13.
11. Process according to claim 10, wherein R1 is a methyl or pentyl group.
12. Process according to claim 10 or 11, wherein R is a butyl or pentyl group.
13. Process according to claim 10, wherein the compound is chosen from among 1-isopropyl-4-(6-undecanyl)-benzene, 1-iospropjl-4- (2-heptanyl)-benzene, or 1-isopropyl-4-(2-hexanyl)-benzene.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9613885A FR2755687B1 (en) | 1996-11-14 | 1996-11-14 | ISOPROPYL-1 DIALKYLMETHYL-4 BENZENE, PROCESS FOR THE PREPARATION AND USE AS AN INHIBITOR OF FREE RADICAL FORMATION |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9722186D0 GB9722186D0 (en) | 1997-12-17 |
| GB2319393A true GB2319393A (en) | 1998-05-20 |
| GB2319393B GB2319393B (en) | 2000-07-19 |
Family
ID=9497615
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9722186A Expired - Fee Related GB2319393B (en) | 1996-11-14 | 1997-10-22 | Use of a 1-isopropyl-4-dialkyl methyl benzene compound as an inhibitor of the formation of free radicals |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH10153686A (en) |
| KR (1) | KR19980042447A (en) |
| FR (1) | FR2755687B1 (en) |
| GB (1) | GB2319393B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2011696A (en) * | 1977-12-28 | 1979-07-11 | Us Energy | Method for recovering palladium and technetium values from nuclear fuel reprocessing wast solutions |
| EP0110789A1 (en) * | 1982-12-01 | 1984-06-13 | Commissariat A L'energie Atomique | Process for recovering actinides and/or lanthanides present in their trivalent state in an aqueous acidic solution |
| US5443731A (en) * | 1994-07-21 | 1995-08-22 | The United States Of America As Represented By The United States Department Of Energy | Process for extracting technetium from alkaline solutions |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL50120A (en) * | 1976-07-25 | 1981-03-31 | Yeda Res & Dev | Process for the extraction of metal ions from solutions using polymer impregnated with extraction agent |
| JPH0819493B2 (en) * | 1986-06-23 | 1996-02-28 | ミヨシ油脂株式会社 | Solvent extractant |
| US4731497A (en) * | 1986-12-29 | 1988-03-15 | Atlantic Richfield Company | Alkylation of aromatics with alpha-olefins |
| KR910000014B1 (en) * | 1987-08-24 | 1991-01-19 | 나기전 | Cu-alloy having a gold or silver color and the method |
| FR2642562B1 (en) * | 1989-02-01 | 1991-04-05 | Commissariat Energie Atomique | PROCESS FOR THE EXTRACTION OF URANIUM VI AND / OR PLUTONIUM IV FROM AN ACID AQUEOUS SOLUTION USING A MIXTURE OF N, N-DIALKYLAMIDES, FOR USE IN THE TREATMENT OF IRRADIATED NUCLEAR FUELS |
-
1996
- 1996-11-14 FR FR9613885A patent/FR2755687B1/en not_active Expired - Fee Related
-
1997
- 1997-10-22 GB GB9722186A patent/GB2319393B/en not_active Expired - Fee Related
- 1997-11-14 KR KR1019970060155A patent/KR19980042447A/en active IP Right Grant
- 1997-11-14 JP JP31366997A patent/JPH10153686A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2011696A (en) * | 1977-12-28 | 1979-07-11 | Us Energy | Method for recovering palladium and technetium values from nuclear fuel reprocessing wast solutions |
| EP0110789A1 (en) * | 1982-12-01 | 1984-06-13 | Commissariat A L'energie Atomique | Process for recovering actinides and/or lanthanides present in their trivalent state in an aqueous acidic solution |
| US5443731A (en) * | 1994-07-21 | 1995-08-22 | The United States Of America As Represented By The United States Department Of Energy | Process for extracting technetium from alkaline solutions |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10153686A (en) | 1998-06-09 |
| FR2755687B1 (en) | 1998-12-04 |
| GB9722186D0 (en) | 1997-12-17 |
| GB2319393B (en) | 2000-07-19 |
| KR19980042447A (en) | 1998-08-17 |
| FR2755687A1 (en) | 1998-05-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Belford et al. | Influence of fluorine substitution on the properties of metal chelate compounds—I Copper (II) chelates of bidentate ligands | |
| Kuang et al. | Extraction and separation of heavy rare earths from chloride medium by α-aminophosphonic acid HEHAPP | |
| Ohto et al. | Selective extraction of silver (I) over palladium (II) with ketonic derivatives of calixarenes from highly concentrated nitric acid | |
| Mincher et al. | The effects of radiation chemistry on solvent extraction 3: a review of actinide and lanthanide extraction | |
| Tan et al. | Highly efficient extraction separation of uranium (VI) and thorium (IV) from nitric acid solution with di (1-methyl-heptyl) methyl phosphonate | |
| Letsinger et al. | α-versus β-Elimination in the Cleavage of Ethers by Organoalkali Metal Compounds | |
| Dixon et al. | Fluorenyllithium-Lewis base complexes | |
| Ireland et al. | Reactions of pentahapto-cyclohexadienyliron tricarbonyl cations with enamines | |
| JP6775572B2 (en) | New asymmetric N, N-dialkylamides, their synthesis and use | |
| Wang et al. | Selective extraction of americium (III) over europium (III) ions in nitric acid solution by NTAamide (C8) using a novel water-soluble bisdiglycolamide as a masking agent | |
| Wang et al. | Novel extractant (2, 4-dimethylheptyl)(2, 4, 4′-trimethylpentyl) phosphinic acid (USTB-2) for rare earths extraction and separation from chloride media | |
| Dong et al. | Separation of thorium from rare earths with high-performance diphenyl phosphate extractant | |
| CN108085491B (en) | A kind of method that neutrality phosphine extractant is used for extraction and separation thorium | |
| Ueda et al. | Extraction Performance of a Fluorous Phosphate for Zr (IV) from HNO3 Solution: Comparison with Tri-n-Butyl Phosphate | |
| Goralski et al. | Hydroboration. 81. Synthesis of 2-(dialkylamino) boronic esters and acids via hydroboration of enamines. A convenient preparation of. beta.-dialkylamino alcohols | |
| Molle et al. | High-yield direct synthesis of a new class of tertiary organolithium derivatives of polycyclic hydrocarbons | |
| Wu et al. | The effective separation of yttrium and other heavy rare earth elements with salicylic acid derivatives | |
| Wan et al. | Photoaddition of water and alcohols to 3-nitrostyrenes. Structure-reactivity and solvent effects | |
| Menon et al. | Synthesis and extraction results of new halide terminated 2-alkyl-p-tert-butylcalix [4] arenes bearing phosphine oxides or ketones on the narrow rim | |
| GB2319393A (en) | Use of a 1-propyl-4-dialkyl benzene compound as an inhibitor of the formation of free radicals | |
| Barnard | Identification and characterisation of a Cyanex 272 degradation product formed in the Murrin Murrin solvent extraction circuit | |
| Cainelli et al. | Chemistry of alkali metal tetracarbonylferrates. Synthesis of aldehydes and reductive dehalogenation by a polymer-supported iron carbonyl complex | |
| Eadon et al. | Mass spectrometry in structural and stereochemical problems. CLXXXVIII. Electron impact induced behavior of branched ketones and esters, with special emphasis on hydrogen rearrangements | |
| Bassetti et al. | Metalation of alkynes. 5. Reaction of diphenylethyne with mercuric salts in alcohols. Synthesis, stereochemistry, and structure of (. beta.-alkoxyvinyl) mercury adducts | |
| Wang et al. | Convenient synthesis of (o-CF 3 Ph) 2 PS 2 H and evaluation in selective extraction of actinides over lanthanides |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20031022 |