Collect. Czech. Chem. Commun. 1984, 49, 840-851

Alternative synthesis of 4-methyl-2H-1,2,6-thiadiazin-3(6H)-one 1,1-dioxide, a structural analogue of thymine

Miroslav Ledvina and Jiří Farkaš

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


N-Alkylsulfamides react with methyl 3-methoxy-2-methyl-2-propenoate (XI) in aqueous hydrochloric acid under formation of methyl 3-(N' -alkylsulfamido)-2-methyl-2-propenoates (VIIa to VIIc). Attempted base-catalyzed cyclization of the ester VIIb was unsuccessful. The 2-benzyl derivative IV and the 6-benzyl derivative V were prepared by reaction of iodotrimethylsilane with the acid VIII and the amide IX, respectively. Hydrogenolytic removal of the benzyl groups in the 2- and 6-benzyl derivatives IV and V afforded the title compound III.