Trifluoroacetic acid → 3(R)-amino-N-(l(S)-benzyl-2-hydroxyethyl)succinamic acid benzyl ester trifluoroacetate salt

Participants

Reaction Steps

To a solution of N-(1(S)-benzyl-2-hydroxyethyl)-3 (R)-(t-butoxycarbonylamino) succinamic acid benzyl ester (389 mg, 0.851 mmol) in CH2Cl2 (5 mL) was added trifluoroacetic acid (1 mL). After 2.5 h at ambient temperature, the solvent was removed in vacuo to give 3(R)-amino-N-(1(S)-benzyl-2-hydroxyethyl)succinamic acid benzyl ester trifluoroacetate salt as a yellow foam that was placed with 3-(biphenyl-4-yl-)2,5-dimethoxytetrahydrofuran (182 mg, 0.641 mmol) in HOAc (1 mL) and heated to 50° C. After 2 hours, the mixture was allowed to cool, carefully stirred with saturated aqueous NaHCO3 (25 mL), and extracted into CHCl3 (3×15 mL). The combined organic layers were dried over Na2SO4 and evaporated to give a brown oil, 685 mg. Flash column chromatography with 10% MeOH/CH2Cl2 as eluant provided 276 mg (64%) of N-(1(S)-benzyl-2-hydroxyethyl)-3(R)-(3-(biphenyl-4-yl)-1H-pyrrol-1-yl)succinamic acid benzyl ester as a yellow solid.

Provenance & Evidence