Water → 1-[(4-bromophenyl)sulfonyl]-4-piperidinecarboxylic acid

Participants

Reaction Steps

Sodium hydroxide solution (100 ml at 40% w/v) was added to a stirred suspension of the above ester (78.0 g) in ethanol (200 ml)/water (100 ml). Water (100 ml) was added and the reaction mixture heated to reflux and reflux maintained for 30 minutes. The reaction mixture was cooled and the crystalline sodium salt was collected. This sodium salt was suspended in water (350 ml) and glacial acetic acid added to adjust the pH of the solution to 5. The mixture was stirred for 1 hour and the colourless solid collected, washed with water and dried to give, as a colourless solid, 1-(4-bromophenylsulphonyl)piperidine-4-carboxylic acid (68.4 g): m.p. 225-227° C.; microanalysis, found: C, 41.0; H, 3.7; N, 3.9%; C12H14BrNO4S requires: C, 41.4; H, 4.1; N 4.0%; NMR: 1.41-1.63(m, 2H), 1.73-1.93(m, 2H), 2.11-2.30(m, 1H), 2.44(t, 2H); 3.28-3.60(m, 2H), 7.62(d, 2H) 7.89(d, 2H).

Provenance & Evidence