Triethanolamine → N-((2R,3S)-3-Amino-2-hydroxy-4-phenylbutyl)-N-(2-methylpropyl)-4-aminobenzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

(1S,2R)-{1-benzyl-2-hydroxy-3-[isobutyl-(4-nitro-benzenesulfonyl)-amino]-propyl}-carbamic acid tert-butyl ester (3, 100 g), 10% palladium carbon (10 gm) and triethanolamine (2 gm) were suspended in isopropyl alcohol. The reaction was heated to 40-45° C. and maintained under 4-6 kg/cm2 of hydrogen pressure for 3 hours. After completion of reaction, the mass was filtered and hydrochloric acid (70 mL) was added to the filtered mass. The solution was heated to reflux and maintained for 2-3 hours. After completion of reaction the mass was cooled to 25-35° C., the reaction mass pH was adjusted to 6.0-7.0 with 20% sodium hydroxide solution and distilled out isopropyl alcohol under vacuum at below 55° C. Ethanol (200 mL) and water (400 mL) was added to the distillate, the mass pH was adjusted to 9.0-10.0 with 20% sodium hydroxide solution at 25-35° C. and maintained the stirring for 2 hours at 25-35° C. The mass was cooled to 0-5° C., filtered and wash with water. The wet product was taken into ethanol (350 mL), maintained the stirring for 30 minutes at reflux temperature. The mass was cooled to 2-4° C., stirred for 2 hours, filtered and washed with ethanol (50 mL). The wet product was dried under normal drying to get title compound 1 (Yield 60 g).

Provenance & Evidence