Hydrochloric Acid → 3-Ethyl-4-(1-piperidinyl)benzoic acid

Participants

Reaction Steps

3-ethyl-4-(1-piperidinyl)benzonitrile (D12) (817 mg, 3.82 mmol) and potassium hydroxide (2.14 g, 38.2 mmol) in ethanol (35 mL) and water (8 mL) were heated to 90° C. (block temperature) for 9 h. Further potassium hydroxide (2.14 g, 38.2 mmol) and water (8 mL) were added and the reaction heated for a further 18 h. The reaction was allowed to cool and was neutralised with aqueous HCl. A white solid was collected by filtration and an attempt was made to purify the filtrate by SCX cartridge, but this failed. Both the solid and product of SCX were combined, methanol added and then the mixture acidified with acetic acid. The mixture was filtered to obtain the filtrate, which was then trapped on SCX cartridge, washed with methanol and eluted with 2M ammonia in methanol. On test scale this gave the title compound as a white solid (96 mg, 0.41 mmol) and on the remaining material gave a colourless oil (563 mg, 2.41 mmol). δH (methanol-d4, 400 MHz): 7.85 (1H, d), 7.74 (1H, dd), 7.03 (1H, d), 2.85 (4H, dd), 2.73 (2H, q), 1.72 (4H, m), 1.61 (2H, m), 1.25 (3H, t) ppm. MS (ES): C14H19NO2 requires 233; found 234 (MH+).

Provenance & Evidence