Racemic 1,1-dimethylethyl 7-[2-(2-tritylaminothiazol-4-yl)-2-methoxyimino-acetamido]-3-(ethoxycarbonylmethylthio)-8-oxo-4-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylate → Racemic 7-[2-(2-aminothiazol-4-yl)-2-methoxyimino-acetamido]-3-(ethoxycarbonylmethylthio)-8-oxo-4-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 200 mg of the product of Step B dissolved in 4 ml of 66% formic acid was stirred at 50° C. for 2 hours, after which the solution was cooled and filtered. The filtrate was concentrated to dryness under reduced pressure and the residue was re-dissolved in ethanol. The solvent was evaporated and 20 ml of ether were added with stirring for 30 minutes. Then, the crude products was separated and chromatographed on silica and eluted with a mixture of methylene chloride and methanol (8-2). After crystallization from ether, 70 mg of racemic 7-[2-(2-aminothiazol-4-yl)-2-methoxyimino-acetamido]-3-(ethoxycarbonylmethylthio)-8-oxo-4-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid melting at >210° C. (decomposes) were obtained.

Provenance & Evidence