摘要 |
NEW MATERIAL:A compound of formula I [X is halogen: Y and Z incorporate to form a group, =NR<5> (R<5> is protected hydroxyl)], its salt or ester. EXAMPLE:Ethyl alpha-ethoxyimino-2-aminothiazol-4-ylacetate hydrobromide. USE:A synthetic intermediate of antibacterials. PREPARATION:The customary halogenation of a compound of formula II such as a beta-ketobutyric acid bearing a protected oxyimino group in the alpha-position gives the compound of formula I . In the compound of formula I , methyl, phenyl or acetyl is cited as a protecting group for the hydroxyl and methyl, tolyl or benzyl for the carboxyl. The protected oxyimino group has syn- and anti-forms theoretically. |