Hydrochloric Acid → 4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-nitroBenzenesulfonamide

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Reaction Steps

(R)-4-(4-Morpholino-4-oxo-1-(phenylthio)butan-2-ylamino)-3-nitrobenzenesulfonamide (INTERMEDIATE 73, 523.6 mg, 1.09 mmol) was dissolved under a nitrogen atmosphere in a solution of borane-THF complex (1M in THF; 2.4 ml, 2.4 mmol) and the resulting solution was stirred at room temperature overnight. The flask was opened to atmosphere and cautiously treated with MeOH (1.20 ml) followed by concentrated HCl (0.48 ml). The resulting mixture was heated at reflux for 3 hours and was then allowed to cool to room temperature. The pH of the mixture was adjusted to approximately 10 by the addition of aqueous solution of Na2CO3 (4 M) resulting in a precipitate. The mixture was dissolved in EtOAc (75 ml) and washed with water (40 ml), brine (40 ml), and dried (Na2SO4). Evaporation of the volatiles under reduced pressure afforded a concentrate, which was purified by column chromatography (ISCO, 40 g silica gel column, eluting with 0→100% EtOAc/hexanes) to provide the title product (406.6 mg, yield: 80%).

Provenance & Evidence