Hydrochloric Acid → 1-{[1-(1-Ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzimidazole-5-carbonyl]-amino}-cycloheptanecarboxylic acid methyl ester

Participants

Reaction Steps

To a solution of 160 mg of 1-(1-ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzoimidazole-5-carboxylic acid (The preparation of intermediates is described below) in 3 ml of dry DMF 73 mg of HOAT, 131 mg of EDC and 0.16 ml of DIPEA were added at 0° C. After 15 min 100 mg of methyl 1-amino-cycloheptanecarboxylate-hydrochloride and 0.16 ml of DIPEA were added and the reaction was stirred at it for 16 h. The reaction was then poured into water and the pH was adjusted to 3 by the addition of 2 M aqueous hydrochloric acid. The reaction was extracted with ethyl acetate three times. The combined organic phases were washed with saturated aqueous sodium bicarbonate solution and brine, dried over magnesium sulphate and concentrated. The crude product was purified by HPLC to yield 200 mg (85%) of 1-{[1-(1-Ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzimidazole-5-carbonyl]-amino}-cycloheptanecarboxylic acid methyl ester.

Provenance & Evidence