Hydrochloric Acid → 4-(2-Methyl-cyclopentylamino)-3-(2-thiophen-2-yl-acetylamino)-benzoic acid methyl ester

Participants

Reaction Steps

To a solution of 3.44 g of thiophen-2-yl-acetic acid in 40 ml of dry DMF 3.62 g of HOAT, 6.48 g of EDC and 12 ml of DIPEA were added at 0° C. After 30 min 6.00 g of 3-Amino-4-(2-methyl-cyclopentylamino)-benzoic acid methyl ester were added, and the reaction was stirred at rt 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. Ethyl acetate was added and the layers were separated. The aqueous layer 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 to obtain 9.03 g (100%) of 4-(2-Methyl-cyclopentylamino)-3-(2-thiophen-2-yl-acetylamino)-benzoic acid methyl ester, which was used without further purification.

Provenance & Evidence