Water → p-Nitrobenzyl 3-Methyl-2-(2-chlorosulfinyl-4-oxo-3-phenoxyacetamido-1-azetidinyl)-3-butenoate

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Reaction Steps

Toluene (425 ml.) was heated in equipment containing a Dean-Stark water trap to azeotropically remove any moisture which may be present, and 25 ml. of toluene were removed thereby. To the remaining toluene were added 10.0 g. (20 mmol.) of p-nitrobenzyl 6-phenoxyacetamido-2,2-dimethylpenam-3-carboxylate-1-oxide, the toluene being maintained at a temperature slightly below reflux. Toluene (200 ml.) was separately distilled, and 4.0 g. (22 mmol.) of N-chlorophthalimide were added. The resulting solution (warm) was added dropwise to the solution of the penicillin sulfoxide ester over a period of 30 minutes. The mixture remained a light yellow solution throughout addition. The mixture then was refluxed for 55 minutes after which time a sample was removed, and nmr (CDCl3) analysis of the sample indicated virtually entire conversion of the penicillin sulfoxide ester to the title compound.

Provenance & Evidence