NOVEL FORTIMICIN DERIVATIVE

摘要

NEW MATERIAL:A substitution product of fortimicin A expressed by formula I [R1, R2, R3 and R4 are H or formula V (R5 is H, alkyl or aryl; R6 is alkyl, hydroxyalkyl, aryl, etc.)] and a pharmacologically acceptable acid addition salt thereof. EXAMPLE:4-N-(N-Benzyloxymethyloxycarbonylglycyl)fortimicin B. USE:An antimicrobial agent capable of increasing the amount to be absorbed orally. PROCESS:A compound expressed by formula II (A is protecting group of the amino group) is acylated with a formic acid derivative expressed by formula VI (Y is Cl, Br etc.; X is Cl, Br or I) to give a compound expressed by formula III, which is then reacted with a carboxylic acid salt expressed by the formula R6COOM (M is alkali metal or organic base) to afford a compound expressed by formula IV. The protecting groups (A) of the amino groups in the resultant compound are then removed to give the compound expressed by formula I in which R1 is a group expressed by formula V and R2, R3 and R4 are H (formula I').