(R/S)-3-(3-Methyl-2-butylamino)-4H-pyrido[4,3-e]-1,2,4-thiadiazine 1,1-dioxide monohydrate

The crystal structure of the title compound, C11H16N4O2S .H2O, a pancreatic B-cell selective K-ATP channel opener, reveals that that the N-alkylsulfonylguanidine moiety of the drug containing the two guanidine NH groups in the same spatial orientation (in parallel) is closely related to the N-alkylcyanoguanidine moiety of pinacidil in the solid state. The results confirm that the title drug may be considered as a hybrid compound between pinacidil and diazoxide. The crystal packing involves four hydrogen bonds which link the drug and water molecules.