Acetonitrile → HCID 69224057, compound

Participants

Reaction Steps

tert-butyl N-((1S,2R)-1-benzyl-3-(cyclohexyloxy)[(4-methoxyphenyl)sulfonyl]amino-2-hydroxypropyl)carbamate (0.09 mmol, 50 mg) was stirred in 1 mL trifluoroacetic acid (TFA) at room temperature for 5 hours. The TFA was removed under vacuum, and the resulting residue was dissolved in ethyl acetate, washed with 5% aq. potassium carbonate solution, brine, dried over magnesium sulfate, and concentrated to a residue. The resulting free amine, 1,3-dioxan-5-yl 4-nitrophenyl carbonate (0.09 mmol, 25 mg), diisopropylethylamine (0.14 mmol, 0.024 mL), a crystal of N,N-dimethylaminopyridine, 4 Å molecular sieves and acetonitrile (0.5 mL) were combined and stirred at room temperature for 20 hours. The reaction solution was concentrated to a residue, dissolved in ethyl acetate, washed with 1N HCl, 5% aq. potassium carbonate solution, brine, dried over magnesium sulfate, and concentrated under vacuum. The crude residue was purified by silica gel chromatography (2:1 hexanes/ethyl acetate) and crystallization from ether and hexanes to yield 10 mg (19%) of white solid. Rf=0.2 (2:1 hexanes/ethyl acetate); H1-NMR (CDCl3): δ 7.69 (2H,d), 7.29-7.18 (6H,m), 6.96 (2H,d), 5.01-4.93 (1H, m), 4.93-4.85 (1H,m), 4.74-4.70 (1H,m), 4.51-4.45 (1H,m), 4.22-4.11 (1H,m), 3.95-3.72 (7H,m), 3.86 (3H,s), 3.00-2.80 (3H,m), 2.10-1.97 (2H,m), 1.79-1.67 (2H,m), 1.61-1.53(2H,m), 1.38-1.02 (6H,m); MS (ESI): M+H=580.

Provenance & Evidence