4-Nitrophenyl 1,3-thiazol-5-ylmethyl carbonate → Thiazol-5-ylmethyl ((1S,2S,4S)-1-benzyl-4-(((1,1-dimethylethoxy)carbonyl)amino)-2-hydroxy-5-phenylpentyl)carbamate

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Reaction Steps

The product of Example 68D (6.0 g , 15.6 mmoles) was dissolved in 60 mL of DMF under nitrogen atmosphere. To this stirred solution at room temperature was added 5-(p-nitrophenyloxycarbonyloxymethyl)thiazole (4.67 g 15.6 mmole) and the resulting solution was stirred for 4h. The solvent was removed under reduced pressure by rotary evaporation and the residue dissolved in 150 mL EtOAc. This solution was washed with 5×75 mL 1N NaOH solution, 100 mL brine, dried over Na2SO4. The solvent was removed to afford 8.02 g of a slightly yellowish oil. This material was crystallized from 30 mL EtOAc and 40 mL hexane to afford 6.53 g (80%) of the desired product as a white solid. mp 118°-120° C. H 1NMR (CDCl3) δ 8.79 (s, 1H), 7.83 (s, 1H), 7.30-7.15 (m, 8H), 7.08 (m, 2H), 5.23 (s, 2H), 5.14 (d, 1H, J=9 Hz), 4.52 (m, 1H), 3.92-3.72 (m, 3H), 3.65 (m, 1H), 2.85 (d-apparent, 2H, J=7.5 Hz), 2.72 (d-apparent, 2H, J=7 Hz), 1.61 (m, 2H), 1.38 (s, 9H). CIMS m/z (526) (M+H)+, 543 (M+18)+.

Provenance & Evidence