N-[(3-Bromo-1-phenylsulfonyl-1H-indol-2-yl)methyl]-4-fluoroaniline

Abstract

In the title compound, C 21 H 16 BrFN 2 O 2 S, the indole ring system makes dihedral angles of 87.23 (10) and 77.58 (9) with the fluorobenzene and phenyl rings, respectively. The molecular structure is stabilized by a C-HÁ Á ÁO and a C-HÁ Á ÁBr intramolecular hydrogen bond, which generate S(6) and S(8) ring motifs, respectively. In the crystal, molecules are linked by C-HÁ Á Á interactions, forming ribbons propagating along the a-axis direction. Within the ribbons, there are offset -interactions present involving inversion-related molecules [intercentroid distance = 3.650 (1) Å ]. Structure descriptionIndole is an important heterocyclic system because it is built into proteins in the form of the amino acid tryptophan as well as being the basis of drugs such as indomethacin and providing the skeleton of indole alkaloids, the biologically active compounds from plants (Sharma et al., 2010). As part of our investigations of indole derivatives, we have undertaken the synthesis and crystal structure analysis of the title compound.The molecular structure of the title compound is shown in Fig. 1. The molecular structure is stabilized by a C-HÁ Á ÁO and a C-HÁ Á ÁBr intramolecular hydrogen bond, which generate S(6) and S(8) ring motifs, respectively ( Fig. 1 and Table 1). The indole ring system (N2/C8-C15) adopts a planar conformation with a maximum deviation of 0.0340 (1) Å for atom C11. Atom F1 deviates by 0.0107 (1) Å from the plane of the benzene ring (C1-C6) to which it is attached. The mean plane of the indole ring system makes dihedral angles of 87.23 (10) and 77.58 (9) with the fluorobenzene and phenyl (C16-C21) rings, respectively. The fluorobenzene and phenyl rings are inclined to one another by 81.44 (11). The indole and fluorobenzene rings are connected through the data reports atoms N1 and C7 with torsion angle C8-C7-N1-C4 = 66.9 (3) . Atom S1 has a distorted tetrahedral configuration. The widening of angle O1-S1-O2 = 119.87 (10) and narrowing of angle N2-S1-C16 = 105.53 (8) from the ideal tetrahedral value are attributed to the Thorpe-Ingold effect (Bassindale, 1984).In the crystal, molecules are linked by C-HÁ Á Á interactions, forming ribbons propagating along the a-axis direction (Table 1 and Fig. 2). Within the ribbons there are offsetinteractions involving inversion-related molecules [Cg3Á Á ÁCg3 iii = 3.650 (1) Å ; Cg3 is the centroid of the C10-C15 ring; interplanar distance = 3.440 (1) Å ; slippage 1.22 Å ; symmetry code: (iii) Àx + 2, Ày + 2, Àz + 1]. Synthesis and crystallizationA solution of 1-phenylsulfonyl-2-bromomethyl-3-bromoindole (1.07 g, 2.5 mmol, 1.0 equiv) and 4-fluoroaniline (0.27 g, 2.5 mmol, 1.0 equiv) in dry DMF (10 ml) containing finely powdered K 2 CO 3 (0.69 g, 5.0 mmol, 2.0 equiv) was stirred at room temperature for 12 h. The reaction mixture was then poured onto ice (200 g) and the solid formed was filtered immediately and washed with an excess of water. The crude product was dried over CaCl 2 and recrystallized from ethyl acetate-hexane (1: 9) to give a half-white coloured so...