p-Toluenesulfonic acid → 2-[4-(Benzthiazol-2-yldithio)-2-oxo-3-phenoxyacetaminoazetidin-1-yl]-3-methyl-3-butenoic acid diphenylmethyl ester

Participants

Reaction Steps

400 mg of 40% aqueous p-toluenesulphonic acid and 1.55 g (17 mmol) of isopropyl nitrite are added to a solution of 4.0 g (8 mmol) of 3-methyl-2-(3-phenoxymethyl-7-oxo-4-thia-2,6-diazabicyclo[3.2.0]hept-2-en-6-yl)-3-butenoic acid diphenylmethyl ester in 12 ml of methylene chloride and the solution is stirred for 6 hours at room temperature with the exclusion of light. A solution of 1.67 g (10 mmol) of 2-mercaptobenzthiazole in 30 ml of ethyl acetate is then added dropwise in the course of 30 minutes and the whole is stirred for a further 12 hours at room temperature. After this period, the thin layer chromatogram indicates almost complete conversion to the title compound. Working up is carried out in a manner analogous to that described in Example 2 (a). The title compound has a melting point of 140°-141°.

Provenance & Evidence