¹⁵N and ¹³C NMR spectroscopy of 1,2,6‐thiadiazine 1,1‐dioxide derivatives and fused systems

Abstract

Abstract The natural abundance 15 N NMR spectra of sulphamide, sixteen 1,2,6‐thiadiazine and two 1,2,4,6‐thiatriazine derivatives, phenylbutazone and antipyrine have been recorded for the first time. The influence of substituents on nitrogen chemical shifts and the effect of intercalation of SO 2 and CO groups between two nitrogen atoms are discussed. Prototropic tautomerism was also studied. 13 C NMR data for some of the 1,2,6‐thiadiazine and thiatriazine derivatives are reported.