A New Method for the Preparation of (E)-2-(Styrylsulfonyl)acetic Acid Esters and Their Reactions with Hydrazine Hydrate

Abstract

A new route to esters of (E)-2-(styrylsulfonyl)acetic acid has been developed. Treatment of the methyl ester with hydrazine hydrate gave the six-membered 4-amino-5-phenylthiomorpholine-3-one 1,1-dioxide (1), and not the seven-membered 6-phenyl-1,4,5-thiadiazepane-3-one 1,1-dioxide (2) as previously described by others. In contrast, treatment of the ethyl ester with the same reagent provided a separable 1:1.2 mixture of 1 and 2. The NMR spectra of both 1 and 2 differed substantially from that described for 2 in the previous report.

Key words

cyclizations - sulfones - heterocycles - esters

References

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