Hydrochloric Acid → 5-chloro-2-(piperazine-1-sulfonyl)-1H-indole

Participants

Reaction Conditions

Reaction Steps

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.

Provenance & Evidence