WO1994003061A1

WO1994003061A1 - Fungicidal process

Info

Publication number: WO1994003061A1
Application number: PCT/GB1993/001471
Authority: WO
Inventors: Patrick Jelf Crowley; David Youle; Stephen Paul Heaney
Original assignee: Zeneca Limited
Priority date: 1992-08-03
Filing date: 1993-07-14
Publication date: 1994-02-17
Also published as: GB9216441D0; ZA935133B; CN1082317A; AU4576793A

Abstract

Process for combating the pathogen Plasmopara viticola which comprises applying to plants or to their locus c^_i^_s^_-2-aminocyclopentane-1-carboxylic acid, c^_i^_s^_-2-aminocyclopent-3-ene-1-carboxylic acid, the (1R^_, 2S^_) form of either, a salt, ester or lactam thereof or a composition containing the same.

Description

FUNGICIDAL PROCESS

This invention relates to cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid, their (IR, 2 ) forms and to salts, esters and lactams thereof. More particularly, it relates to their use as fungicides.

(lR,2S)-Cis-2-aminocyclopentane-l-carboxylic acid is known and described in, for example, J. Antibiotics, Vol X II, No 12, 1749 and 1756 (1989); J. Antibiotics Vol XLIII, No 1, 1(1990) and J. Antibiotics Vol XLIII, No 5, 513(1990). Its antifungal activity is also described. The use of cis-2-aminocyclopentane-l-carboxylic acid and its salts and esters as agricultural microbiocides is disclosed in JP 63083004 and JP 63287753.

Cis-2-aminocyclopent-3-ene-l-carboxylic acid, certain of its salts and esters and their use as agricultural microbiocides are disclosed in JP 63287754.

In JP 6308004, JP 63287753 and JP 63287754, tests are described which show the microbiocidal activity of the foregoing compounds against the pathogens: Phytophthora infestans (tomato blight), Pyricularia oryzae (rice leaf blast), Pseudoperonospora cubensis (cucumber downy mildew), Fusarium oxysporu f. sp. cucumerium (cucumber Fusarium wilt) and Alternaria brassicicola (Chinese cabbage sooty disease).

It has now been found that cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid, their (IR, 2S) forms and their salts, esters and lactams show exceptional activity against the pathogen Plasmopara viticola (vine downy mildew). Therefore, according to the present invention, there is provided a process for combating the pathogen Plasmopara viticola which comprises applying to plants or to their locus cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3- -ene-1-carboxylic acid, the (IR, Z^~ ) form of either, a salt, ester or lactam thereof or a composition containing the same.

Alternatively, the invention provides a process for combating fungi which comprises applying to vines or to their locus cis-2-aminocyclo- pentane-1-carboxylic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid, the (IR, 2 ) form of either, a salt, ester or lactam thereof or a composition containing the same.

Any vines may be treated but the invention is of particular interest for the treatment of vines of the genus Vitis, especially the sub-genus Euvitis, which may be of American, Asiatic or Euro-asiatic stock, and more especially the species Vitis vinifera, and also the species V.riparia, V.rupestris, V.berlandieri and V.labrusca.

Thus, in a preferred embodiment, the invention provides a process for combating the pathogen Plasmopara viticola which comprises applying to vines of the genus Vitis or to their locus, cis-2-aminocyclopentane-l- -carboxylic acid, cis-2-aminocyclopent-3-ene-l-carbox lic acid, the (IR, 2 ) form of either, a salt, ester or lactam thereof or a composition containing the same.

The invention is of particular value for the preventative control of vine downy mildew. Consequently, it is preferred that the vines or their locus are treated when threatened by the disease prior to significant infection.

Salts of cis-2-aminocyclopentane-l-carboxylic acid, cis-2-amino- cyclopent-3-ene-l-carboxylic acid and their (IR, 2 ) forms include acidic and basic salts, for example, salts of inorganic acids such as hydrochloride salts, salts of organic acids such as tosylate salts and alkali metal salts such as sodium and potassium salts and alkaline earth metal salts.

Esters include alkyl, alkenyl and alkynyl esters where the alkyl group contains, for instance, from 1 to 8 carbon atoms in straight or branched chains and the alkenyl and alkynyl groups contain, for instance, from 3 to 8 carbon atoms in straight or branched chains. Examples are methyl, ethyl, n-propyl, iso-propyl, n-, iso- and tert-butyl, allyl and propargyl. Salts of esters, such as the hydrochloride salt of esters, are included.

The lactams of the invention are the internal amides of cis-2-amino- cyclopentane-1-carboxylic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid and their (IR, 2 ) forms.

Examples of specific compounds which may be used in the process of the invention are:

Cis-2-aminocyclopentane-l-carboxylic acid (compound 1)

The hydrochloride salt of cis-2-aminocyclopentane-l-carboxylic acid

(compound 2)

The methyl ester of cis-2-aminocyclopentane-l-carboxylic acid

(compound 3)

The hydrochloride salt of cis-2-aminocyclopent-3-ene-l-carboxylic acid (compound 4)

The lactam, 6-azabicyclo[3.2.0]hept-3-en-7-one (compound 5) Cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3-ene- -1-carboxylic acid, and their salts and esters can be prepared from the lactams 6-azabicyclo[3.2.0]heptane-7-one and 6-azabicyclo[3.2.0]hept-3-en- -7-one, respectively, as described in Isr. J. Chem. , 10:55, [1972], J. Antibiotics, 42:1749, [1989], JP 63287753 and JP 63287754. For example, the hydrochloride salts of cis-2-aminocyclopentane-l-carboxylic acid and cis-2-aminocyclopent-3-ene-l-carbox lic acid can be prepared by treating the appropriate lactam with concentrated hydrochloric acid. The products may be converted to their free bases and esterified or converted to other salts by conventional techniques.

The lactams, which themselves show exceptional activity against the pathogen Plasmopara viticola, can be prepared by the methods described in J. Antibiotics. , 42:1749, [1989] and in J. Chem. Res, (microfiche), 3283, [1978]. In these methods, chlorosulphonyl isocyanate is reacted at low temperature with cyclopentene or cyclopentadiene, as appropriate, and the chlorosulphonyl lactam so formed treated with potassium iodide and sodium bisulphate followed by sodium hydroxide, or with a mixture of sodium bicarbonate and sodium metabisulphite, to remove the chlorosulphonyl group.

The (IR, 2 ) form of cis-2-aminocyclopentane-l-carboxylic acid can be prepared by a fermentation process as described in EP-A1-0 298 640 or by the optical resolution of a derivative of cis-2-aminocyclopentane-l- -carboxylic acid as described in JP 02049758.

The (IR, 2 ) form of cis-2-aminocyclopent-3-ene-l-carboxylic acid can be prepared by the optical resolution of a derivative of cis-2-aminocyclo- pent-3-ene-l-carboxylic acid using standard methods.

The invention compounds (ie cis-2-aminocyclopentane-l-carbox lic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid, their (IR, 2 ) forms and their salts, esters and lactams) will normally be applied to vine plants as a foliar spray, but they may also be applied to stems, branches, roots or seedlings or to soil surrounding the roots. They may also be injected into plants or sprayed using electrodynamic spraying techniques or other low volume methods. They can also be applied in the form of a cream or paste or slow release granules or a vapour.

When applied to the foliage of plants, the compounds are applied at rates of O.lg to 10kg, preferably lg to 8kg, more preferably lOg to 4kg, of active ingredient per hectare. The compounds may be used directly but are more conveniently formulated into compositions using a carrier or diluent. The type of composition used in any instance will depend upon the particular purpose envisaged.

The compositions may be in the form of dustable powders or granules comprising the active ingredient and a solid diluent or carrier, for example, fillers such as kaolin, bentonite, kieselguhr, dolomite, calcium carbonate, talc, powdered magnesia, fuller's earth, gypsum, diatomaceous earth and china clay. Such granules can be preformed granules suitable for application to the soil without further treatment. These granules can be made either by impregnating pellets of filler with the active ingredient or by pelleting a mixture of the active ingredient and powdered filler. Compositions for dressing seed may include an agent (for example, a mineral oil) for assisting the adhesion of the composition to the seed; alternatively the active ingredient can be formulated for seed dressing purposes using an organic solvent (for example, N-methylpyrrolidone, propylene glycol or N^N-dimethylformamide) . The compositions may also be in the form of water dispersible powders or water dispersible granules comprising wetting or dispersing agents to facilitate the dispersion in liquids. The powders and granules may also contain fillers and suspending agents.

The compositions may also be in the form of soluble powders or granules, or in the form of solutions in polar solvents.

Soluble powders may be prepared by mixing the active ingredient with a water-soluble salt such as sodium bicarbonate, sodium carbonate, magnesium sulphate or a polysaccharide, and a wetting or dispersing agent to improve water dispersibility/solubility. The mixture may then be ground to a fine powder. Similar compositions may also be granulated to form water-soluble granules. Solutions may be prepared by dissolving the active ingredient in polar solvents such as ketones, alcohols and glycol ethers. These solutions may contain surface active agents to improve water dilution and prevent crystallisation in a spray tank.

Emulsifiable concentrates or emulsions may be prepared by dissolving the active ingredient in an organic solvent optionally containing a wetting or emulsifying agent and then adding the mixture to water which may also contain a wetting or emulsifying agent. Suitable organic solvents are aromatic solvents such as alkylbenzenes and alkylnaphthalenes, ketones such as cyclohexanone and methylcyclohexanone, chlorinated hydrocarbons such as chlorobenzene and trichlorethane, and alcohols such as benzyl alcohol, furfuryl alcohol, butanol and glycol ethers.

Aqueous suspension concentrates of largely insoluble solids may be prepared by ball or bead milling with a dispersing agent with a suspending agent included to stop the solid settling.

Compositions to be used as sprays may be in the form of aerosols wherein the formulation is held in a container under pressure of a propellant, e.g. fluorotrichloromethane or dichlorodifluoromethane.

The invention compounds can be mixed in the dry state with a pyrotechnic mixture to form a composition suitable for generating in enclosed spaces a smoke containing the compounds.

Alternatively, the compounds may be used in micro-encapsulated form. They may also be formulated in biodegradable polymeric formulations to obtain a slow, controlled release of the active substance.

By including suitable additives, for example additives for improving the uptake, distribution, adhesive power and resistance to rain on treated surfaces, the different compositions can be better adapted for various utilities. Other additives may be included to improve the biological efficacy of the various formulations. Such additives can be surface active materials to improve the wetting and retention on surfaces treated with the formulation and also the uptake and mobility of the active material, or additionally can include oil based spray additives, for example, certain mineral oil and natural plant oil (such as soya bean and rape seed oil) additives, or blends of them with other adjuvants.

The invention compounds can be used as mixtures with fertilisers (e.g. nitrogen-, potassium- or phosphorus-containing fertilisers). Compositions comprising only granules of fertiliser incorporating, for example coated with, a compound are preferred. Such granules suitably contain up to 25Z by weight of the compound.

Water dispersible powders, emulsifiable concentrates and suspension concentrates will normally contain surfactants, e.g. a wetting agent, dispersing agent, emulsifying agent or suspending agent. These agents can be cationic, anionic or non-ionic agents.

Suitable cationic agents are quaternary ammonium compounds, for example, cetyltrimethylammonium bromide. Suitable anionic agents are soaps, salts of aliphatic monoesters of sulphuric acid (for example, sodium lauryl sulphate), and salts of sulphonated aromatic compounds (for example, sodium dodecylbenzenesulphonate, sodium, calcium or ammonium lignosulphonate, butylnaphthalene sulphonate, and a mixture of sodium diisopropyl- and triisopropylnaphthalene sulphonates) .

Suitable non-ionic agents are the condensation products of ethylene oxide with fatty alcohols such as oleyl or cetyl alcohol, or with alkyl phenols such as octyl- or nonylphenol and octylcresol. Other non-ionic agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, alkyl glucosides, polysaccharides and the lecithins and the condensation products of the said partial esters with ethylene oxide. Suitable suspending agents are hydrophilic colloids (for example, polyvinylpyrrolidone and sodium carboxymethylcellulose), and swelling clays such as bentonite or attapulgite.

Compositions for use as aqueous dispersions or emulsions are generally supplied in the form of a concentrate containing a high proportion of the active ingredient, the concentrate being diluted with water before use. These concentrates should preferably be able to withstand storage for prolonged periods and after such storage be capable of dilution with water in order to form aqueous preparations which remain homogeneous for a sufficient time to enable them to be applied by conventional spray equipment. The concentrates may conveniently contain up to 952, suitably 1-85Z, for example 1-25Z or 25-60Z, by weight of the active ingredient. After dilution to form aqueous preparations, such preparations may contain varying amounts of the active ingredient depending upon the intended purpose, but an aqueous preparation containing 0.0001 to 10Z, for example 0.005 to 10Z, by weight of active ingredient may be used.

The compositions may contain other compounds having biological activity, e.g. compounds having similar or complementary fungicidal activity or which possess plant growth regulating, herbicidal or insecticidal activity.

An additional fungicidal compound may be present in the composition. By including another fungicide, the resulting composition can have a broader spectrum of activity or a greater level of intrinsic activity than the invention compound alone. Further, the other fungicide can have a synergistic effect on the fungicidal activity of the compound. Examples of fungicidal compounds which may be included in the composition are (RS)-l-aminopropylphosphonic acid, (RS)-4-(4-chloro-phenyl)-2-phenyl-2- -(1H-1,2,4-triazol-1-ylmethyl)butyronitrile, ( Z )-N-but-2-en loxymethyl-2- -chloro-2' ,6'-diethylacetanilide, 1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea, 4-(2,2-difluoro-l,3-benzodioxol-4-yl)pyrrole-3-carbonitrile, 4-bromo- -2-cyano-N,N-dimethyl-6-trifluoromethylbenzimidazole-l-sulphonamide, 5-ethyl-5,8-dihydro-8-oxo(1,3)-dioxol-(4,5-£)quinoline-7-carboxylic acid, α-[N-(3-chloro-2,6-xylyl)-2-methoxyacetamido]-*y-butyrolactone, N-(2-π_ethoxy-5-pyridyl)-cyclopropane carboxamide, methyl (E)-2-{2-[6-(2- -cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate, alanycarb, aldimorph, ampropylfos, anilazine, azaconazole, BAS 490F, benalaxyl, benomyl, biloxazol, binapacryl, bitertanol, blasticidin S, bromuconazole, bupirimate, butenachlor, buthiobate, captafol, captan, carbendazim, carbendazim chlorhydrate, carboxin, chinomethionate, chlorbenzthiazone, chloroneb, chlorothalonil, chlorozolinate, clozylacon, copper containing compounds such as copper oxychloride, copper oxyquinolate, copper sulphate, copper tallate and Bordeaux mixture, cycloheximide, cymoxanil, cyproconazole, cyprofuram, debacarb, di-2-pyridyl disulphide 1,1'-dioxide, dichlofluanid, dichlone, diclobutrazol, diclomezine, dicloran, didecyl dimethyl ammonium chloride, diethofencarb, difenoconazole, 0,0-di-iso- -propyl-S-benzyl thiophosphate, dimefluazole, dimetconazole, dimethomorph, dimethirimol, diniconazole, dinocap, dipyrithione, ditalimfos, dithianon, dodemorph, dodine, doguadine, edifenphos, epoxiconazole, etaconazole, ethirimol, ethoxyquin, ethyl (Z -N-benzyl-N-( [methyl(methylthioethyl- ideneamino-oxycarbonyl)amino]thio)-β-alaninate, etridiazole, fenaminosulph, fenapanil, fenarimol, fenbuconazole, fenfuram, fenpiclonil, fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide, ferbam, ferimzone, fluazinam, fludioxonil, fluoroimide, fluquinconazole, flusilazole, flutolanil, flutriafol, folpet, fuberidazole, furalaxyl, furconazole-cis, guazatine, hexaconazole, hydroxyisoxazole, hymexazole, imazalil, imibenconazole, ipconazole, iprobenfos, iprodione, isopropanyl butyl carbamate, isoprothiolane, kasugamycin, mancozeb, maneb, mepanipyrim, mepronil, metalaxyl, metconazole, methfuroxam, metiram, metiram-zinc, metsulfovax, myclobutanil, neoasozin, nickel dimethyldithiocarbamate, nitrothal-isopropyl, nuarimol, ofurace, organomercury compounds, oxadixyl, oxolinic acid, oxycarboxin, pefurazoate, penconazole, pencycuron, phenazin oxide, phosetyl-Al, phosphorus acids, phthalide, polyoxin D, polyram, probenazole, prochloraz, procymidone, propamocarb, propamocarb hydrochloride, propiconazole, propineb, propionic acid, prothiocarb, pyracarbolid, pyrazophos, pyrifenox, pyrimethanil, pyroquilon, pyroxyfur, pyrrolnitrin, quaternary ammonium compounds, quinconazole, quinomethionate, quintozene, rabenazole, sodium pentachlorophenate, streptomycin, sulphur, tebuconazole, techlofthalam, tecnazene, tetraconazole, thiabendazole, thicyofen, thifluzamide, 2-(thiocyanomethylthio)benzothiazole, thiophanate-methyl, thira , timibenconazole, tolclofos-methyl, tolylfluanid, triacetate salt of l,l'-iminodi(octamethylene)diguanidine, triadi efon, triadimenol, triazbutyl, triazoxide, tricyclazole, tridemorph, triforine, triflumizole, triticonazole, validamycin A, vapam, vinclozolin, XRD-563, zineb and ziram. The invention compounds can be mixed with soil, peat or other rooting media for the protection of plants against seed-borne, soil-borne or foliar fungal diseases.

It is preferred that all compositions, both solid and liquid formulations, comprise 0.0001 to 95Z, more preferably 1 to 85Z, for example 1 to 25Z or 25 to 60Z, of an invention compound.

The following examples illustrate the invention. Abbreviations used in reporting the NMR data are as follows:

s ■ singlet m « multiplet d - doublet dd ■ double doublet t « triplet dt - double triplet q ■ quartet br - broad

EXAMPLE 1 Preparation of the hydrochloride salt bf cis-2-aminocyclopent-3-ene-l- -carboxylic acid (compound 4).

Stage 1 : Preparation of 6-azabicyclo[3.2.0]hept-3-en-7-one (compound 5). Freshly distilled cyclopentadiene (7.18g, 8.96ml, 0.109mol) in dry diethyl ether (10ml) was gradually added with vigorous stirring, under an atmosphere of nitrogen, to a solution of chlorosulphonyl isocyanate (14.Og, 8.61ml, 0.099mol) in dry diethyl ether (25ml) at -60°C. Stirring was continued at -60° for 1% hours. The reaction mixture was gradually added to a vigorously stirred mixture of sodium bicarbonate (27g) and sodium metabisulphite (2g) in water (90ml) at 0°C. After filtration and washing of the solid residue with diethyl ether and water, the organic and aqueous filtrates were separated and the aqueous filtrates twice re-extracted with diethyl ether. The combined organic phases were washed with brine, dried over anhydrous magnesium sulphate and concentrated under reduced pressure to yield an oil/solid suspension. The suspension was triturated with diethyl ether and filtered. The filtrate (1.4g) was combined with material from other, similar experiments and distilled under reduced pressure in a k gelrohr apparatus (ca. 200°C at 12 mmHg) to give 6-azabicylo[3.2.0]hept- -3-en-7-one as a very pale yellow oil; IR maxima (film): 3650-3050, 1740 cm^"1; ¹H NMR (CDC1₃) δ: 2.36-2.55(1H,dd) , 2.65-2.81(lH,m) , 3.75-3.90(lH,brdt), 4.51(lH,s), 5.90-5.98(lH,m) , 5.99-6.07(lH,m) , 6.38(lH,brs).

Stage 2 : Preparation of title product.

6-Azabicyclo[3.2.0]hept-3-en-7-one (0.660g) was added to concentrated hydrochloric acid (4ml) at 0°C with stirring and maintained at this temperature for about 1% hour before adding acetone. The mixture was cooled and the solid material filtered, washed with acetone and air-dried to yield the title product (0.559g; 57Z yield) m.p. 179.5-181.5°C; IR maxima (nujol): 3340, 3240, 3200-2450, 1712, 1575, 1490, 1410, 1203; ¹H NMR (D O) δ: 2.62-2.85(2H,m), 3.51(lH,q), 4.32(lH,brd) , 5.74-5.84(lH,m) , 6.18-6.28(lH,m).

EXAMPLE 2 Compounds 1 to 5 were tested against the pathogen Plasmopara viticola by the following general method.

Vine plants were grown in John Innes Potting Compost (No 2) in 4cm diameter minipots. The compounds were formulated either by bead milling with aqueous Dispersol T or as a solution in acetone or acetone/ethanol which was diluted to the required concentration immediately before use. The formulations (100 ppm active ingredient) were sprayed on to the foliage and applied to the roots of the plants in the soil. The sprays were applied to maximum retention and the root drenches to a final concentration equivalent to approximately 40 ppm a.i. in dry soil.

The compounds were applied to the soil (roots) and to the foliage (by spraying) one day before the plant was inoculated with the disease. The foliar pathogen Plasmopara viticola was applied by spray as a zoosporangial suspension onto the leaves of test plants. After inoculation, the plants were put into an appropriate environment to allow infection to proceed and then incubated until the disease was ready for assessment. The period between inoculation and assessment was six days.

The disease level present (ie leaf area covered by actively sporulating disease) on each of the treated plants was recorded using the following assessment scale: 0 = 0Z disease present 20 = 10.1-20Z disease present

1 = 0.1-1Z disease present 30 = 20.1-30Z disease present 3 = 1.1-3Z disease present 60 «= 30.1-60Z disease present 5 » 3.1-5Z disease present 90 - 60.1-100Z disease present

10 = 5.1-10Z disease present

Each assessment was then expressed as a percentage of the level of disease present on the untreated control plants. This calculated value is referred to as a P0C0 (Percentage of Control) value. An example of a typical calculation is as follows:

Disease level on untreated control = 90 Disease level on treated plant * 30 disease level on treated plant

POCO = x 100 - 30 x 100 - 33.3 disease level on untreated control 90

This calculated POCO value is then rounded to the nearest of the values in the 9-point assessment scale shown above. In this particular example, the POCO value would be rounded to 30. If the calculated POCO falls exactly mid-way between two of the points, it is rounded to the lower of the two values.

Compounds 1 to 5 all gave a POCO value of 0 (ie no disease present) when tested by this method.

Claims

1. A process for combating the pathogen Plasmopara viticola which comprises applying to plants or their locus cis-2-aminocyclopentane-l- -carboxylic acid, cis-2-aminocyclopent-3-ene-l-carboxylic acid, the (IR, 2S_) form of either, a salt ester or lactam thereof or a composition containing the same.

2. A process for combating fungi which comprises applying to vines or their locus cis-2-aminocyclopentane-l-carboxylic acid, cis-2-amino- cyclopent-3-ene-l-carboxylic acid, the (IR, 2S form of either, a salt, ester or lactam thereof or a composition containing the same.

3. A process for combating the pathogen Plasmopara viticola which comprises applying to vines of the genus Vitis or to their locus cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3- -ene-1-carboxylic acid, the (IR, 2 ) form of either, a salt, ester or lactam thereof or a composition containing the same.

4. A process for the preventative control of the pathogen Plasmopara viticola on vines of the genus Vitis which comprises applying to vines threatened by infection from the pathogen or to their locus cis-2-aminocyclopentane-l-carboxylic acid, cis-2-aminocyclopent-3- -ene-1-carboxylic acid, the (IR, 2ja) form of either, a salt, ester or lactam thereof or a composition containing the same.

5. A process according to any one of claims 1 to 4 in which is applied cis-2-aminocyclopentane-l-carboxylic acid.

6. A process according to any one of claims 1 to 4 in which is applied cis-2-aminocyclopent-3-ene-l-carboxylic acid.

7. A process according to any one of claims 1 to 4 in which is applied the hydrochloride salt of cis-2-aminocyclopentane-l-carboxylic acid.

8. A process according to any one of claims 1 to 4 in which is applied the hydrochloride salt of cis-2-aminocyclopent-3-ene-l-carboxylic acid.