| 摘要 |
This invention relates to a process for the manufacture of peptide derivatives of the general formula (I) wherein n stands for 1, 2 or 3; R1 is methyl and R2 and R3 are methyl, isopropyl or isobutyl with the proviso that R3 is methyl when n is 1; R4 represents a hydroxy or methyl group; the configuration at the carbon atom designated as (a) is D; the configuration at the carbon atom designated as (b) is L; and the configuration at the carbon atom denoted as (c) is (R), and of pharmaceutically acceptable salts thereof, which process comprises (a) cleaving off the protecting group(s) present in a compound of the general formula (II) wherein n, R1, R and R3 have the significances given above; R40 represents a methyl group or R41; R41 represents a hydroxy group or lower alkoxy protecting group; R5 represents a hydrogen atom or a protecting group; and the configurations at the carbon atoms designated as (a), (b) and (c) are as defined above, or (b) separating an (R,S)-diastereomeric compound corresponding to formula I into its diastereomers and isolating the (R)diastereomer, and, if desired, converting an obtained compound of formula I into a pharmaceutically acceptable salt. me peptide derivatives of formula I potentiate the activity of D-cycloserine. In addition, they possess an antibacterial activity against organisms such as Escherichia coli, Klebsiella aerogenes, Streptococcus faecalisand Haemophilus influenzae. |
