N -(1-Allyl-1 H -indazol-5-yl)-4-methoxybenzenesulfonamide hemihydrate

In the title compound, C17H17N3O3.0.5H2O, the indazole system makes a dihedral angle of 46.19 (8)° with the plane through the benzene ring and is nearly perpendicular to the allyl group, as indicated by the dihedral angle of 81.2 (3)°. In the crystal, the water molecule, disordered over two sites related by an inversion center, forms O-H...N bridges between indazole N atoms of two sulfonamide molecules. It is also connected via N-H...O interaction to the third sulfonamide molecule; however, due to the water molecule disorder, only every second molecule of sulfonamide participates in this interaction. This missing interaction results in a slight disorder of the sulfonamide S,O and N atoms which are split over two sites with half occupancy. With the help of C-H...O hydrogen bonds, the molecules are further connected into a three-dimensional network.