| abstract |
A novel process for the preparation of ceftiofur, a cephalosporin antibiotic useful in the treatment of bovine respiratory disease using a novel bromo or chloro intermediate. the process comprises of the steps of cyclizing a new bromo or chloro intermediate with thiourea in the presence of selected solvents to produce ceftiofur of high purity. A process to prepare such novel bromo and chloro intermediate comprising of the steps of condensing silylated Furaca with 4-(bromo or chloro)-2 methoxyamino-3-oxobutyric acid or its acid halide is also described. |