| 摘要 |
NEW MATERIAL:The compound of formula I [R<1> is H or alkyl; R<2> is (protected) hydroxymethyl, carbamoyl, or alkylcarbamoyl; R<3> is H, light metal atom or carboxy-protecting group]. EXAMPLE:7beta-( Carboxamidofluorovinylthioacetamido )-3-( 1-hydroxymethyl-1H-tetrazol-5-yl)thiomethyl-1-dethia-1-oxa-3-cephem-4- carboxylic acid. USE:Antibacterial agent. PREPARATION:The compound of formula I can be prepared e.g. by O-silylating the 4-carboxylic acid on the 1-dethia-1-oxacephem ring of the 7beta-amino compound of formula II with trimethylsilyl chloride, etc., reacting the product with the chloride of the carboxylic acid compound of formula III in the presence of pyridine, and decomposing the reaction product with a silyl ester. |
