Diisopropylethylamine → 1-(1-Ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzoimidazole-5-carboxylic acid ((S)-1-cyanomethyl-3-methyl-butyl)-amide

Participants

Reaction Steps

To a solution of 4.93 g of 1-(1-ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzoimidazole-5-carboxylic acid in 50 ml of dry DMF 2.04 g of HOAT, 3.45 g of EDC and 4.35 ml of DIPEA were added at 0° C. After 30 min 3.29 g of (S)-3-Amino-5-methyl-hexanenitrile-hydrochloride and 4.35 ml of DIPEA were added and the reaction was stirred at rt for 4 h. The reaction was then poured into water and the pH was adjusted to 3 by the addition of 2 M aqueous sodium hydrogensulphate solution. 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. 5.90 g (90%) of 1-(1-Ethyl-propyl)-2-thiophen-2-ylmethyl-1H-benzoimidazole-5-carboxylic acid ((S)-1-cyanomethyl-3-methyl-butyl)-amide were obtained.

Provenance & Evidence