NEW THIAZOL COMPOUNDS AND THEIR PREPARATIONS

摘要

The present invention relates to a new crystalline aminothiazole derivative represented by the following formula (I) which is very useful for the preparation of cephalosporin antibiotics, including ceftazidime and cefixime, etc:wherein R1 and R2 are the same or different and independently represent H, an alkyl group of 1 to 4 carbon atoms, or a cycloalkyl group of 3 to 5 carbon atoms, X represents chlorine or bromine, and the acid in the acid addition salt represents an inorganic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, or perchloric acid, or an organic acid, such as formic acid, acetic acid, trifluoroacetic acid, propionic acid, methanesulfonic acid, or benzenesulfonic acid.