Hydrochloric Acid → 5-chloro-2-(piperazine-1-sulfonyl)-1H-indole
Reaction equation
C1(S([N:10]2[C:18]3[C:13](=[CH:14][C:15]([Cl:19])=[CH:16][CH:17]=3)[CH:12]=[C:11]2[S:20]([N:23]2[CH2:28][CH2:27][NH:26][CH2:25][CH2:24]2)(=[O:22])=[O:21])(=O)=O)C=CC=CC=1.[OH-].[Na+].Cl>>[Cl:19][C:15]1[CH:14]=[C:13]2[C:18](=[CH:17][CH:16]=1)[NH:10][C:11]([S:20]([N:23]1[CH2:28][CH2:27][NH:26][CH2:25][CH2:24]1)(=[O:22])=[O:21])=[CH:12]2Participants
4
Conditions
- Temperature
- 80 °C
Procedure
The requisite 1-(5-chloroindol-2-ylsulphonyl)piperazine starting material was prepared as follows 1-(1-Benzenesulphonyl-5-chloroindol-2-ylsulphonyl)piperazine (4.15 g, 9.44 mmol) was treated with sodium hydroxide solution (32 ml of 2.5M), giving a yellow suspension. This was warmed to 80° C. with vigorous stirring and stirred for 45 mins, giving complete solution. The solution was cooled to ambient temperature and carefully treated with concentrated hydrochloric acid to pH 8; the resultant precipitate was filtered off, washed with water and dried to give 1-(5-chloroindol-2-ylsulphonyl)piperazine as a pale yellow solid, 1H NMR (d6DMSO) 2.75 ppm (m, 4H), 2.9 ppm (m, 4H), 7.0 ppm (s, 1H), 7.3 ppm (dd, 1H), 7.5 ppm (d, 1H), 7.8 ppm (d, 1H); MS (M+H)+ 300/302.