Process for the selective N-acylation of aminohydroxamic acid derivatives and starting materials used therein

Claim 1

A process for the manufacture of a compound of formula I ##STR11## in which Ac is C 2 -C 20 -alkanoyl, benzoyl, C 18 -alkenoyl, (C 1 -C 12 -alkoxy)carbonyl, a radical of the formula --CO--O--(CH 2 --CH 2 --O--) n -lower alkyl in which n is from 1 to 19, chlorocarbonyl, (1-imidazolyl)-carbonyl, N-di-lower alkylcarbamoyl, N-(C 1 -C 5 -alkyl)-carbamoyl substituted in the 1- or 2-position of the alkyl moiety by (C 1 -C 4 -alkoxy)-carbonyl, N-(chlorosulfonyl)-carbamoyl, N-(lower alkoxysulfonyl)-darbamoyl or a radical of the formula --SO 2 --NH--CO(--O--CH 2 --CH 2 ) n -lower alkoxy in which n is from 0 to 19, and A 1 , A 2 and A 3 are each hydrogen, characterized in that a compound of formula II ##STR12## in which each pf B, B o 1 , B o 2 and B o 3 is an organic silyl group (sil) of formula ##STR13## wherein R s 1 and R s 2 , independently of one another, are each C 1 -C 8 -alkyl, phenyl, p-tolyl, benzyl or phenethyl and R s 3 is C 1 -C 8 -alkyl, phenyl, p-tolyl, benzyl, phenethyl or chlorine, is reacted with an acylating agent selected from the group consisting of (1) Ac 4 Y, wherein Ac 4 is C 2 -C 20 -alkanoyl, benzoyl, C 18 -alkenoyl, (C 1 -C 20 -alkoxy)-carbonyl, a radical of the formula --CO--O--(CH 2 --CH 2 --O--) n -lower alkyl in which n is from 1 to 19, chlorocarbonyl, (1-imidazolyl)carbonyl, N-di-lower alkylcarbamoyl, N-(C 1 -C 5 -alkyl)-carbamoyl substituted in the 1- or 2-position of the alkyl moiety by (C 1 -C 4 -alkoxy)carbonyl, or a radical of the formula --SO 2 --NH--CO(--O--CH 2 --CH 2 ) n -lower alkoxy in which n is from 0 to 19, and Y is chlorine, 1-imidazolyl, bromine or azido, (2) chlorosulfonylisocyanate, (3) R 4 --N═C═O wherein R 4 is C 1 -C 5 -alkyl substituted in the 1- or 2-position of the alkyl moiety by (C 1 -C 4 -alkoxy)-carbonyl, (4) Ac 5 --O--Ac 5 , wherein Ac 5 is C 2 -C 20 -alkanoyl, benzoyl, C 18 -alkenoyl, (C 1 -C 12 -alkoxy)-carbonyl, a radical of the formula --CO--O--(CH 2 --CH 2 --O--) n -lower alkyl in which n is from 1 to 19, chlorocarbonyl, and (5) R 3 ═C═O wherein R 3 is C 2 -C 20 -alkylidene or C 18 -alkenylidene, and solvolytically splitting off the O-bonded organic silyl groups Sil present by treatment with a lower alkanol.