Reactivity of 5-Methyl-2H -1,2,6-thiadiazin-3(6H )-one 1,1-Dioxide towards Alkylating Agents and Carbenes

Abstract

The reaction between SlnethyZ-ZH-l,2,6-thiadiazin-3f6H)-one 1 , Idioxide _I and a variety of alkytating ugents (diuzomethane, trimethyl phosphit e , dimethyl sulfate, and methyl iodide) i n different conditions has been studied.Five methyl derivatives have been isolated and chamcterized.The reaction betueen 2 and carbenes proceeds with d i f f i c u l t y and only i n the case of the carbene obtained from ethyl diazoacetate has the nddition product been isolated.Compound !, 5-methyl-ZH-l,Z,6-thiadiazin-3(6H)-one 1.1-dioxide, is an isosteric analog of 6-methyluracil in which a carbonyl group is replaced by a sulfone group.'This molecule has four different nucleophilic positions, namely N2, 03, Cq, and N6, thus, four monosubstituted, six disubstituted, and three trisubstituted derivatives may be expected from alkylation reactions.