Trifluoroacetic acid → 2(R)-[(3,4-methylendioxybenzyl)-(2,6-dimethyl-4-methoxybenzenesulfonyl)amino]-3-[(2-pyrrol-1-yl)phenylcarbonylamino]-propionic acid

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Reaction Steps

A solution of tert-butyl-2(R)-[(3,4-methylendioxybenzyl)-(2,6-dimethyl-4-methoxybenzenesulfonyl)amino]-3-[(2-pyrrol-1-yl)phenylcarbonylamino]-propionate (915 mg, 1.3 mmol) in 20% trifluoracetic acid-methylene chloride (15 ml) was stirred for 1 hour. Extra trifluoroacetic acid (0.5 ml) was added and stirring continued for 1.5 hours. The material was then condensed on the rotary evaporator and the residue was taken up in toluene (40 ml) and again condensed. This procedure was repeated twice (2×40 ml toluene, to remove traces of trifluoracetic acid) to provide 2(R)-[(3,4-methylendioxybenzyl)-(2,6-dimethyl-4-methoxybenzenesulfonyl)amino]-3-[(2-pyrrol-1-yl)phenylcarbonylamino]-propionic acid as a golden tan solid (896 mg).

Provenance & Evidence