4a-Methyl-2,3,4,4a-tetrahydro-1H-carbazole-6-sulfonamide

In the title molecule, C13H16N2O2S, the nine non-H atoms comprising the indole residue are approximately coplanar (r.m.s. deviation = 0.031 Å). The partially saturated ring adopts a chair conformation. One amine H forms an intermolecular N—H⋯O hydrogen bond to a sulfonamide O atom, while the other amine H form is connected to the indole N atom of an adjacent molecule via an N—H⋯N hydrogen bond, resulting in a three-dimensional architecture.

In the title molecule, C 13 H 16 N 2 O 2 S, the nine non-H atoms comprising the indole residue are approximately coplanar (r.m.s. deviation = 0.031 Å ). The partially saturated ring adopts a chair conformation. One amine H forms an intermolecular N-HÁ Á ÁO hydrogen bond to a sulfonamide O atom, while the other amine H form is connected to the indole N atom of an adjacent molecule via an N-HÁ Á ÁN hydrogen bond, resulting in a three-dimensional architecture.
In (I), Fig. 1, the partially saturated ring adopts the conformation of a chair. The nine non-carbon atoms of the indole residue are co-planar, having a r.m.s. deviation of 0.031 Å. With reference to this plane, the C1-C6 ring and the amino group lie to one side, with the methyl group and one sulphonamide-O atom being orientated to the other.
Strong hydrogen bonding interactions dominate the crystal packing. Thus, one amino-H forms a hydrogen bond to the sulphonamide-O1 atom while the others forms a hydrogen bond to the indole-N atom, Table 1. The result is a threedimensional architecture, Fig. 2.
Experimental 1-Methylcyclohexanone (1.1 g, 10 mmol) in ethanol was refluxed with p-sulfamylphenylhydrazine (2.2 g, 10 mmol) for 1 h. The reaction mixture was cooled and the precipitated solid product was collected by filtration, washed with ethanol, dried and recrystallized from ethanol. Yield: 78%.

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H = 0.95 to 0.99 Å, U iso (H) = 1.2U eq (C)] and were included in the refinement in the riding model approximation. The amino H-atoms were located in a difference Fourier map, and were refined with a distance restraint of N-H = 0.88±0.01 Å; their U iso values were refined.