Study of the structure of Besulpamide, 1-[(4-Chloro-3-sulfamoylbenzoyl)amino]-2,4,6-trimethylpyridinium hydroxide inner salt, and related compounds, using X-ray crystallography and 1H and 13C nuclear magnetic resonance spectroscopy

Article abstract of DOI:10.1002/jhet.5570260527

The diuretic and antihypertensive drug Besulpamide, 1-[(4-Chloro-3-sulfamoylbenzoyl)amino]-2,4,6-trimethylpyridinium hydroxide inner salt, and related compounds have been investigated by nmr spectroscopy and mass spectrometry. A mechanism for the formation of the salt 5 is proposed. The tautomerism of hydroxy derivatives of Besulpamide is discussed on the basis of nmr spectroscopy. The single-crystal X-ray investigation of Besulpamide, R = 0.038 (R_w = 0.041), showed two crystallographically independent molecular conformations in the crystal structure, space group PI, a = 8.485(3), b = 14.282(2), c = 15.312(6), α = 69.41(2), β = 82.22(4), γ = 72.78(3).