SULFO-BIGINELLI REACTION: AN INSIGHT INTO INTERACTION BETWEEN SULFAMIDES AND ENOLIZABLE KETONES

Abstract

The interaction employing sulfamide and enolizable monoketones was closely inspected as sulfo-analogue of reputable Biginelli reaction. The three-component variants of the reaction ‘sulfamide+ketone+anisaldehyde’ and ‘sulfamide+ketone+N,N-diethylacetoacetamide’ featured a lack of selectivity and provided a mixture of all possible condensation products. Selectivity was improved when ketones were used in the reaction as both carbonyl and enol parts. It was shown that trimethylsilyl chloride promoted interaction of sulfamide (1 equiv) with monoketones (2 equiv) afforded 1,2,6-thiadiazines for carbonyl component from different groups. Limitations were noted and unexpected outcomes of the reaction were discussed as well.