Amido Form Research Articles

INFRARED SPECTRA OF SULFONAMIDE DERIVATIVES. I. PYRIDINE, THIAZOLE, AND PYRIMIDINE DERIVATIVES.

The infrared spectra of N-(2-pyridyl)-, N-(2-thiazolyl)-, N-(2-pyrimidinyl)- and N-phenyl-sulfonamide derivatives and their N-deuterated compounds, as well as N1- or ring N-methylsulfonamide derivatives were measured. The spectral changes on N-deuteration suggest that pyrimidine derivatives take the amido form, while pyridine and thiazole derivatives take the imido form. The SO2 symmetric stretching bands of sulfanilamide derivatives may be divided into the two regions, 1170 to 1145 cm-1 and 1145 to 1130 cm-1, according to the amido form and the imido form, respectively.