The Reaction of Diazoalkanes with Heterocumulenes. Mechanism and Synthetic Utility

Abstract

<p>A new approach to the synthesis of 3,3-dialkyloxindole systems which involves reaction of a dialkyldiazomethane, generated (in situ) by the thermolysis of a 5,5-dialkyl-∆³-1,3,4-oxadiazolin-2-one, with an aryl isocyanate, has been developed. Minor products of the reaction are a 2-imino-5,5-dialkyl-4-oxazolidone and a 5,5-dialkylhydantoin. The synthesis of both a 2-imino-5,5-dialkyl-4-thiazolinethione and a 5,5-dialkyl-2,4-dithiohydantoin has been achieved in a similar manner, using phenyl isothiocyanate in place of phenylisocyanate. Spectroscopic data, in particular ¹³C chemical shifts, and chemical transformations are cited in support of the structural assignments. Possible mechanisms for the formation of the heterocyclic compounds are considered.</p>