Process for Manufacture of 9-Amino-9-Deoxyclavulanates

EXAMPLE 1 Benzyl 3-(2-dibenzylaminoethylidene)-7-oxo-1-azabicylo[3.2.0]heptane-2-carboxylat e (e2) ##STR16##

EXAMPLE 2 Methyl 3-(2-dibenzylaminoethylidene)-7-oxo-4-1-azabicyclo[3,2,0]2-carboxylate ##STR17## The compound (e2) (100 mg) in tetrahydrofuran (5 ml) was hydrogenated at ambient temperature and pressure over 10% Pd/C (50 mg) for one hour. The solution was filtered through keirselguhr, the solvent evaporated, the residue dissolved in ethylacetate (10 ml) and extracted with water (4.times.10 ml). The water was evaporated to yield a gum which was dissolved in methanol (5 ml) and treated with excess/diazomethane at 0.degree. C. Evaporation of the solvent and chromatography yield the desired compound (methyl dibenzylamino deoxyclavulanate (e3) as a colourless gum.

EXAMPLE 3 Benzyl N-benzyl-N-2-hydroxyethylamino-deoxyclavulanate ##STR18## Clavudiene benzyl ester (0.5 g) in acetonitrile (10 ml) was cooled to 0.degree. C., N-benzyl-2-hydroxyethylamine (0.36 g) was added and the reaction mixture stirred for 21/2 hours. Ethyl acetate (100 ml) was added and the mixture evaporated to low volume. The residue was subjected to column chromatography using ethyl acetate as eluent. The product, was isolated in low yield had an ir spectrum (liquid film) as follows: 3400 (broad, --OH), 1800 (.beta.-lactam C.dbd.O), 1740 (ester C.dbd.O), 1700 (C.dbd.C), 695 cm.sup.-1 (aromatic protons). The n.m.r. spectrum was consistent with the desired product (e5).

EXAMPLE 4 Benzyl N-benzyl-N-isopropylamino deoxyclavulanate ##STR19## The ester(e4)(0.5 g) in acetronitrile (10 ml) was cooled in ice-water. N-iso propylbenzylamine (0.39 g, 1.3 moles) was added with stirring. The reaction mixture was allowed to warm to room temperature and stirred for 3 hours. Ethyl acetate (100 ml) was added, and the solution evaporated to low bulk in vacuo. The residue was subjected to column chromatography on silica gel using cyclohexane and ethyl acetate as eluents. The product (e6) was eluted after the unreacted diene. It had Ir spectrum (liquid film) as follows: 1803, (.beta.-lactam C.dbd.O) 1845 (ester C.dbd.O) 1700 (C.dbd.C) 695 cm.sup.-1 (aromatic protons). The n.m.r. spectrum was consistent with the desired product

EXAMPLE 5 Benzyl dibenzylaminodeoxyclavulanate ##STR20## Benzyl dichloroacetylclavulanate (e7) (0.8 g) was dissolved in dry dimethylformamide and cooled to 0.degree. C., treated with dibenzylamine (768 .mu.l; 0.004 mol) in dry dimethylformamide (4 ml) over 15 minutes, the temperature being maintained at 0.degree. C. The resulting yellow solution was stirred at 0.degree. for 21/2 hours and a room temperature for 4 hours. Ethylacetate was added (100 ml) and the solution washed with water (3.times.25 ml), dried and evaporated. The product was purified by fast gradient elution on silica gel using ethyl acetate/cyclohexane as the eluting solvent (Yield 0.33 g).

EXAMPLE 6 Benzyl dibenzylaminodeoxyclavulanate ##STR21## The diene (e4) (271 mg) in dry acetonitrile (4 ml) at 0.degree. C. was treated with dibenzylamine (197 mg) in dry acetonitrite (2 ml) over 5 minutes. The reaction mixture was stirred at 0.degree. C. for 2 hours and at room temperature for 2 hours. The solvent was removed by evaporation and the residue dissolved in ethyl acetate, washed with water, dried evaporated and fractionated on silica-gel to yield the desired product (e2) which was purified by chromatography.

EXAMPLE 7 Benzyl N-benzyl-9-(dl-2-hydroxypropylamino-9-deoxyclavulanate ##STR22## Benzyl dichloroacetylclavulanate (e7) (0.8 g) in dry dimethylformamide (20 ml) was cooled to 0.degree. C. and a solution of dl-1-benzylamino-2-propanol (0.65 g) in dry dimethylformamide was added slowly. Stirring was continued for 4 hours at 0.degree. C.

EXAMPLE 8 Benzyl diallylaminodeoxyclavulanate ##STR24## Benzyl dichloroacetylcalvulanate (e7) (0.4 g) was dissolved in dry dimethylformamide (7 mls) and cooled to 0.degree. C. A solution of diallylamine (246 .mu.l; 0.002 mol) in dry dimethylformamide (2 ml) was added the temperature was maintained at 0.degree. C. The solution was stirred for 2 hours at 0.degree. and at 15.degree. for 15 minutes. Ethyl acetate (75 ml) was added and the solution washed with water (2.times.35 ml) dried and evaporated. The more polar product was isolated by column chromatography on silica gel and was obtained as a yellow oil (0.18 g);

EXAMPLE 9 p-Methoxybenzyl diallylaminodeoxyclavulanate ##STR25## The sulphate (e10) (0.46 g) was dissolved in dry dimethylformamide (7 ml) and cooled to 0.degree. C., diallylamine (0.175 g) in dry dimethylformamide (2 ml) was added slowly dropwise. The reaction mixture was stirred at 0.degree. for 2 hours and worked up as in Example 5. Column chromatograph gave the product (e11) as a yellow oil.

EXAMPLE 10 9-(NN-dibenzylamino)-9-deoxyclavulanic acid ##STR26##

EXAMPLE 11 Benzyl N-benzyl-N-norbornylaminodeoxyclavulanate ##STR27##

EXAMPLE 12 9-(N,N-dipropylamino)-9-deoxyclavulanio acid ##STR28##

EXAMPLE 13 9-[DL-N-Benzyl-N-(2-hydroxypropyl)amino]-9-deoxyclavulanic acid ##STR29##

EXAMPLE 14 Activity

PREPARATION 1

General Procedure for Preparation of Sulphonate

PREPARATION 2

General Procedure for Preparation of Diene Esters

EXAMPLE 15 Methyl 2-(N-benzyl) norbonylaminodeoxyclavulanate ##STR30## Sodium clavulanate tetrahydrate (e16) (2.9 g) in dimethylformamide (25 ml) was treated with iodomethane (25 ml) at room temperature over 1 hour. Acetontrile (10 ml) was added and removed by evaporation under reduced pressure (to remove excess methyliodide). The residual dimethylformamide solution was cooled in ice, and phthalic anhydride (1.5 g) and triethylamine (5 ml) added. After 1 hour at below 5.degree. C., acetonitrile (2.times.25 ml portions) was added and evaporated under reduced pressure each time. 2-N-benzylnorbornylamine (4 g) was added and the reaction allowed to stir at 5.degree. C. overnight. Most of the dimethylformamide was evaporated in vacuo. The residue was dissolved in 1:1 ethyl acetate-cyclohexane (100 ml), treated with silica gel (15 g) (chromatography grade), filtered off, evaporated to small bulk, and the residue subjected to gradient chromatography on silica gel using ethyl acetate and cyclohexane as eluents. The least polar .beta.-lactam containing material was isolated by evaporation of the solvents from fractions containing it, to yield methyl 2-(N-benzyl)norbornylaminodeoxyclavulanate (e17) as a yellow oil (50 mg). It had I.r. 1800 (.beta.-lactam) 1750 (ester C.dbd.O) 1695 cm.sup.-1 (C.dbd.C).

EXAMPLE 16 Benzyl N-benzyl-N-ethylaminodeoxyclavulanate ##STR31## Clavudiene benzyl ester (0.44 g) in acetonitrile (8 ml) was cooled to -10.degree. C. and treated with N-benzylethylamine (0.27 g). The reaction mixture was maintained at -5.degree. to 0.degree. C. for 11/2 hours. Ethyl acetate (70 ml) was added and the mixture evaporated to small volume. The residue was subjected to column chromatography on silica gel using a gradient elution, starting with 7:1 cyclohexane/ethyl acetate increasing quickly to 2:1.