Hydrochloric Acid → HCID 22826191, compound

Participants

Reaction Steps

In 50 ml of tetrahydrofuran was dissolved 5.46 g (21.9 mmole) of S-ethyl-N-t-butoxycarbonyl-L-cysteine and 3.05 ml (21.9 mmole) of triethylamine was added thereto. Upon cooling to -15° C., 2.87 ml (21.9 mmole) of isobutyl chloroformate was added dropwise and the mixture was stirred for 20 minutes at that temperature. Upon cooling to -30° C., a solution of 2.79 g (32.9 mmole) of piperidine in 5 ml of tetrahydrofuran was added in one portion and the mixture was stirred for 2.5 hours under ice cooling. After addition of 70 ml of ethyl acetate, the mixture was washed successively with 30 ml of aqueous 5% sodium bicarbonate, 2×30 ml of aqueous 10% citric acid, 2×30 ml of aqueous 5% sodium bicarbonate and 2×30 ml of saturated saline and then dried over anhydrous magnesium sulfate. The resulting solution was concentrated in vacuo to give 6.66 g of S-ethyl-N-t-butyloxycarbonyl-L-cysteine piperidylamide as an oil, 96% yield. ##STR14## A solution of 6.55 g (20.7 mmole) of S-ethyl-N-t-butyloxycarbonyl-L-cysteine piperidylamide in 100 ml of ethyl acetate was added dropwise over 20 minutes to 80 ml of ice-cooled 16% solution of hydrogen chloride in ethyl acetate. After stirring for 3 hours at room temperature, the reaction mixture was concentrated in vacuo, resulting in the formation of crystals. The crystals were collected, washed with ethyl acetate and then with ethyl ether and dried to give 3.66 g of S-ethyl-L-cysteine piperidylamide hydrochloride, 74% yield.

Provenance & Evidence