Three derivatives of 4-fluoro-5-sulfonylisoquinoline

Abstract

In 4-fluoroisoquinoline-5-sulfonyl chloride, C9H5ClFNO2S, (I), one of the two sulfonyl O atoms lies approximately on the isoquinoline plane as a result of minimizing the steric repulsion between the chlorosulfonyl group and the neighbouring F atom. In (S)-(−)-4-fluoro-N-(1-hydroxypropan-2-yl)isoquinoline-5-sulfonamide, C12H13FN2O3S, (II), there are two crystallographically independent molecules (Z′ = 2). The molecular conformations of these two molecules differ in that the amine group of one forms an intramolecular bifurcated hydrogen bond with the F and OH groups, whilst the other forms only a single intramolecular N—H...F hydrogen bond. The N—H...F hydrogen bonds correspond to weak coupling between the N(H) and19F nuclei, observed in the1H NMR solution-state spectra. In (S)-(−)-4-[(4-fluoroisoquinolin-5-yl)sulfonyl]-3-methyl-1,4-diazepan-1-ium chloride, C15H19FN3O2S+·Cl−, (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group.