Chloromethyl chloroformate → Chloromethyl propyl carbonate

Participants

Reaction Conditions

Reaction Steps

Chloromethyl chloroformate (0.027 mL, 0.30 mmol) was added dropwise to a stirred solution of tert-butyl {(1S,2R)-2-[3,5-bis(trifluoromethyl)phenyl]-2-hydroxy-1-methylethyl}{[4′-fluoro-5′-isopropyl-2′-methoxy-4-(trifluoromethyl)biphenyl-2-yl]methyl}carbamate (INTERMEDIATE 7, 209 mg, 0.294 mmol) (200 mg, 0.28 mmol) and proton sponge (60 mg, 0.28 mmol) in dry CH2Cl2 (5.0 mL) at 0° C. under N2. The reaction was stirred at 25° C. for 16 h. The reaction was diluted with water (30 mL) and extracted with EtOAc (3×30 mL). The combined extracts were dried (MgSO4) and concentrated in vacuo to give the crude product. This was purified by flash chromatography (0-20% gradient EtOAc/hexanes over 30 min) to give (1R,2S)-1-[3,5-bis(trifluoromethyl)phenyl]-2-(tert-butoxycarbonyl){[4′-fluoro-5′-isopropyl-2′-methoxy-4-(trifluoromethyl)biphenyl-2-yl]methyl}amino)propyl chloromethyl carbonate as a colorless oil. 1H NMR (500 MHz, CDCl3): δ 7.81-6.82 (m, 8 H); 7.08 (dd, J=8.3 Hz, 8.7 Hz, 1 H); 5.68 (m, 2 H); 4.19-4.16 (d, J=16.7 Hz, 1 H); 4.77 (s, 3 H), 3.31-3.24 (m, 1 H); 1.76 (s, 3 H); 1.41 (s, 3 H); 1.22-1.18 (s, 9 H), 1.04 (d, J=6.6 Hz, 3 H).

Provenance & Evidence