Bosentan monohydrate

In the title compound, C27H29N5O6S·H2O {systematic name: 4-tert-butyl-N-[6-(2-hy-droxy-eth-oxy)-5-(2-meth-oxy-phen-oxy)-2-(pyrimidin-2-yl)pyrimidin-4-yl]benzene-1-sulfonamide monohydrate], the dihedral angle between the mean planes of the pyrimidine rings is 27.0 (1)°. The dihedral angle between the mean planes of the benzene rings is 47.7 (8)°, forming a U-shaped channel around the chain of twisted pyrimidine rings. The crystal packing is stabilized by O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds with a single water mol-ecule, and weak O-H⋯N inter-molecular inter-actions between the hy-droxy group and one of the pyrimidine rings producing an two-dimensional supra-molecular array in the bc plane. The title compound studied was a merohedral twin with the major component being approximately 57%.