Process for the preparation of 3-amino-pyrrolidine derivatives

Abstract: The invention is concerned with a process for the manufacture of 3-amino-pyrrolidine derivatives of the formula wherein R 1 signifies hydrogen, alkyl, cyclo-alkyl, alkenyl, aryl or an amino protecting group; and R 2 , R 3 each independently signify hydrogen, alkyl, cyclo-alkyl, alkenyl or aryl; by converting a compound of the formula wherein X signifies a protected hydroxy group; in the presence of a primary amine of the formula R 1 NH 2 into the pyrrolidine derivative of the formula wherein X and R 1 have the aforementioned significances; which is subsequently reacted in the presence of R 2 R 3 NH under pressure; and with the use of this process for the production of vinylpyrrolidinone-cephalosporin derivatives.

Description: The present invention is concerned with a novel process for the manufacture of racemic and optically active 3-amino-pyrrolidine derivatives and with the use of this process for the production of cephalosporin derivatives. 3-Amino-pyrrolidine derivatives, especially optically active 3-amino-pyrrolidine derivatives, are important intermediates for the production of agrochemicals and of pharmaceutically active substances such as, for example, of vinylpyrrolidinone-cephalosporin derivatives. 3-Amino-pyrrolidine derivatives can be manufactured in a manner known per se, for example as described in EP-A 0 218 249 starting from 1,2,4-trisubstituted butane derivatives such as e.g. tribromobutane or trihydroxybutane. The racemic derivatives can then, if desired, can be converted by a racemate resolution into optically active 3-amino-pyrrolidine derivatives, JP 09124595-A. A process for the manufacture of optically active 3-amino-pyrrolidine derivatives based on the conversion of 4-hydroxy-proline as described, for example, in J . Med. Chem. 1764(92), 35 , gives optically active 3-aminopyrrolidine over 3 steps. The known methods for the manufacture of 3-aminopyrrolidine derivatives as described, for example, in UK Patent No. 1 392 194, EP 0 391 169 and US Patent No. 4 916 141, are time consuming and lead to expensive intermediates. The interest in other processes for the manufacture of 3-amino-pyrrolidine derivatives, especially of optically active 3-amino-pyrrolidine derivatives, is therefore extremely high. It has now been found that 3-amino-pyrrolidine derivatives, especially optically active 3-amino-pyrrolidine derivatives, can be manufactured in high yields in a simple manner from 1,2,4-trihydroxybutane derivatives. The invention is accordingly concerned with a process for the manufacture of 3-amino-pyrrolidine derivatives of the formula wherein * indicates a chiral centre. The process is distinguished over known processes primarily in that on the one hand by virtue of the use of a chiral educt of the formula wherein X is mesylate; the racemate resolution is no longer necessary and on the other hand the number of steps for the manufacture of 3-amino-pyrrolidine derivatives of formula I-a which proceeds with high optical and chemical yields is reduced by appropriate choice of the protecting groups. The process in accordance with the invention for the manufacture of an optically active 3-amino-pyrrolidine derivative of the formula comprises a) converting optically active butyl-1,2,4-trimesylate (methanesulphonic acid 3-methanesulphonyloxy-1-methanesulphonyloxy-methyl-propyl ester, II-a) in the presence of benzylamine in tetrahydrofuran at a temperature of 0°C to 70°C, preferably at 50-60°C, into the corresponding optically active pyrrolidine derivative of formula b) replacing the benzyl group in the pyrrolidine derivative of formula III in the presence of allyl haloformate by allyloxycarbonyl in an inert solvent such as a hydrocarbon e.g. heptane, at temperatures of 0-100°C, preferably of 30-70°C; c) subsequently obtaining the desired optically active 3-amino-pyrrolidine derivative of formula I-a by introducing the amino group in the presence of ammonia, optionally in a solvent, such as e.g. tetrahydrofuran or dimethoxyethane, under pressure, preferably under a pressure of 3x10 6 -2x10 7 PA, especially under a pressure of 5x10 6 -8x10 6 PA, at a temperature of 20-200°C, preferably 100-150°C. The process in accordance with the invention is especially suitable for the manufacture of optically active 1-allyloxycarbonyl-3-amino-pyrrolidine, an intermediate for the production of vinylpyrrolidinone-cephalosporin derivatives of the formula wherein Y signifies CH or nitrogen; R 6 signifies hydrogen or C 1-12 -alkyl; R 4 signifies hydrogen, an alkali metal ion or a tertiary ammonium group or an acid protecting group; R 1 denotes hydrogen, C 1-12 -alkyl or an amino protecting group; * denotes a centre of chirality. Compounds of formula A are cephalosporin derivatives having a high antibacterial activity, especially against methicillin-resistant strains of Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa . Compounds of general formula A can be produced, for example, in a convergent synthesis as described in EP-A-0 849 269 in accordance with Scheme I: The symbols used in Scheme I have the aforementioned significances and R 5 signifies an amino protecting group. The 3-amino-pyrrolidine derivative of formula I-b is reacted with chloro-2-bromobutyroyl chloride and the N-substituted 3-bromopyrrolidone is converted into the Wittig salt (6) which is reacted in accordance with Scheme 1 with the cephemaldehyde (5). The substituted cephem derivative (7) is then reacted with an activated acyl derivative (4) to give the vinylpyrrolidinone-cephalosporin derivative of formula A. The production of vinylpyrrolidinone-cephalosporin derivatives of formula A can be simplified by the use of the process in accordance with the invention, by which the 3-amino-pyrrolidine derivative of formula I-a is accessible with high chemical and optical yields. The present invention relates to the aspects described above and especially also to the use of the process for the manufacture of the compounds of formula I-a and of the compounds of formula A, which are manufactured according to the said processes. The following Examples serve only to illustrate the invention. Example 1 Preparation of methanesulphonic acid 3,4-bis-methanesulphonyloxy-butyl ester. A solution of 18.1 ml of methanesulphonic acid in 45 ml of ethyl acetate is added dropwise within 2 hours under argon to a solution, cooled to 0-5°C, of 7.96 g of S-1,2,4-butanetriol and 33.5 ml of triethylamine in 90 ml of ethyl acetate. The white suspension was stirred at 0-5°C for a further 2 hours and thereafter the suspension was filtered and the yellow filtrate was washed in succession with 75 ml of 1N hydrochloric acid, 75 ml of saturated NaHCO 3 solution and 75 ml of saturated NaCl solution. The organic phase was dried over Na 2 SO 4 , filtered and the filtrate was concentrated. 21.79 g of yellow oil were obtained. Example 2 Preparation of methanesulphonic aicd (S)-1-benzyl-pyrrolidin-3-yl ester. a) 21.8 ml of benzylamine were added dropwise to a solution of 17 g of methanesulphonic acid 3,4-bis-methanesulphonyloxy-butyl ester (from Example 1) in 200 ml of tetrahydrofuran under argon, with the solution warming to 30°C. The solution was boiled at reflux for 24 hours, thereafter cooled to 0-5°C and the benzylammonium salt which thereby precipitated was filtered off. The filtrate was concentrated, the residude was taken up in 150 ml of tert-butyl methyl ether and the emulsion which thereby resulted was saturated with dry ice. After 5 minutes the white slurry was dissolved with 150 ml of water. The organic phase was separated and washed with 50 ml of saturated NaCl solution and with 30 ml of saturated NaCl solution. The washed solution was extracted with 100 ml of tert-butyl methyl ether and the organic phases were combined, dried with Na 2 SO 4 , filtered and the filtrate was concentrated. 12.1 g of yellow oil were obtained. b) 13.8 g of sodium hydride were suspended in 250 ml of tetrahydrofuran under argon and cooled to 0-5°C. Within 1.5 hours there was added dropwise to this suspension a yellow solution of 88.6 g of N-benzyl-3-S-pyrrolidinol in 500 ml of tetrahydrofuran, the mixture was stirred at 0-5°C for 15 minutes and treated dropwise within 2 hours with a solution of 42.74 ml of mesyl choride in 250 ml of tetrahydrofuran. After stirring at 0-5°C for 1 hour the suspension was filtered over speedex, the filtrate was concentrated and the oily residue was taken up in 1000 ml of tert-butyl methyl ether and 280 ml of 3N sodium hydroxide solution. The phases were separated, the organic phase was washed with 250 ml of sodium hydroxide solution. The phases were separated, the organic phase was washed with 250 ml of sodium hydroxide solution and the wash solution was extracted with 500 ml of tert-butyl methyl ether. The organic phases were combined, dried over Na 2 SO 4 , filtered and the filtrate was concentrated. There were obtained 103.24 g of brown oil which was purified by chromatography. 51.44 g of product were obtained. Example 3 Preparation of allyl-3-methanesulphonyloxy-pyrrolidine-1-carboxylate. 6.4 ml of allyl chloroformate were added dropwise to 10.2 g of methanesulphonic acid (S)-1-benzyl-pyrrolidin-3-yl ester in 880 ml of n-heptane at room temperature within 10 minutes under argon and with slight cooling. The two-phase mixture was stirred vigorously for 2 hours 45 minutes and subsequently treated with 40 ml of methanol/water (1:1). The aqueous methanolic phase was separated, extracted with 40 ml of heptane and thereafter the methanol was distilled off on a rotary evaporator. The aqueous phase was extracted twice with 30 ml of ethyl acetate. The organic phases were combined, dried over Na 2 ,SO 4 , filtered and the filtrate was concentrated. 8.23 g of beige oil were obtained. Example 4 Preparation of allyl 3-amino-pyrrolidine-1-carboxylate. 1 g of allyl 3-methanesulphonyloxy-pyrrolidine-1-carboxylate was placed in an autoclave, evacuated 4 times under argon and again exposed to air and subsequently cooled in an acetone/CO 2 bath. The reaction was effected at 8x10 6 PA with ammonia at a temperature of 110°C. After stirring for 90 minutes the autoclave was cooled, the residue was taken up in methylene chloride, the suspension was filtered and the filtrate was concentrated. There was obtained 0.68 g of pale brown oil with an e.e. (enantiomeric excess) of 96.7%. Example 5 Preparation of 1-benzyl-3-amino-pyrrolidine. 1.94 g of methanesulphonic acid (S)-1-benzyl-pyrrolidin-3-yl ester were placed in an autoclave, evacuated 4 times under argon and again exposed to air, and then cooled in an acetone CO 2 bath. The reaction was effected at 8 x10 6 PA with ammonia at a temperature of 110°C. After stirring for 150 minutes the autoclave was cooled, the residue was taken up in methylene chloride, the suspension was filtered and the filtrate was concentrated. 1.33 g of pale brown oil were obtained. After purification by chromatography there were obtained 1.26 g of product with an e.e. (enantiomeric excess) of 96.8%.

Claims: A process for the preparation of an optically active 3-amino-pyrrolidine derivative of the formula wherein * indicates a chiral centre the process comprising a) reacting optically active butyl-1,2,4-trimesylate in the presence of benzylamine in tetrahydrofuran at a temperature of 0°C to 70°C into a compound of formula b) replace the benzyl group in the presence of allyl haloformate by allyloxycarbonyl in an inert solvent at a temperature of 0-100°C; c) then reacting the compound with ammonia under a pressure of 3x10 6 -2x10 7 PA, at a temperature of 20-200°C. Process of claim 1, charcterized in that the compound of formula I-a is further processed to a vinylpyrrolidone-cephalosporin derivative of formula A wherein Y signifies CH or nitrogen; R 6 signifies hydrogen or C 1-12 -alkyl; R 4 signifies hydrogen, an alkali metal ion or a tertiary ammonium group of an acid protecting group; R 1 denotes hydrogen, C 1-12 -alkyl or an amino protecting group; * denotes a centre of chirality.

Inventors: KLINKHAMMER UWE, SPURR PAUL, WANG SHAONING, KLINKHAMMER, UWE, SPURR, PAUL, WANG, SHAONING
Applicants: BASILEA PHARMACEUTICA AG
Application year: 1999
Main classification: C07D207
IPC codes: C07D501, C07D207