Triethylamine → 1-Fluoro-3-((4-fluorophenyl)(isocyano)methyl)-5-(trifluoromethyl)benzene

To a solution of (3-fluoro-5-(trifluoromethyl)phenyl)(4-fluorophenyl)methanamine (315 mg, 1.1 mmol) in CH2Cl2 (2 mL) at 0° C. was added acetic formic anhydride (314 uL, formed by heating a 2:1 v/v ratio of acetic anhydride and formic acid at 60° C. for 2 h). The reaction mixture was allowed to warm to room temperature and stirred for 0.5 h. The reaction mixture was concentrated under reduced pressure and the residue was purified on a 40 g column of silica gel, eluting with 0 to 100% EtOAc/hexane, to give N-((3-fluoro-5-(trifluoromethyl)phenyl)(4-fluorophenyl)methyl)formamide (327 mg, 94% yield) as a clear, viscous oil. LCMS: RT=1.37 min [M+H] 316.1 (2 min Phenomenex Luna C18 column, 4.6×30 mm eluting with 10-90% acetonitrile/H2O over 2 minutes containing 0.1% TFA; 5 mL/min, monitoring at 220 nm); NMR: 400 MHz 1H (CDCl3) δ ppm 6.13 (bs, 1H), 6.34 (d, J=7.47 Hz, 1H), 7.05-7.20 (m, 5H), 7.27-7.34 (m, 2H), 8.35 (s, 1H). To a solution of N-((3-fluoro-5-(trifluoromethyl)phenyl)(4-fluorophenyl)methyl)formamide (327 mg, 1.04 mmol) in THF (5 mL) at 0° C. was added Et3N (0.79 mL, 5.7 mmol) followed by phosphorous oxychloride (0.125, 1.35 mmol). The reaction mixture was allowed to warm to room temperature and stirred for 16 h. The reaction mixture was diluted with ice-water (25 mL) and extracted with Et2O (3×20 mL). The combined organic layers were washed with sat. NaCl (20 mL), dried over anhydrous Na2SO4, the filtered through basic alumina. The filtrate was concentrated to give 1-fluoro-3-((4-fluorophenyl)(isocyano)methyl)-5-(trifluoromethyl)benzene (268 mg, 93% yield) as a pale brown oil. LCMS: RT=1.71 min [M-NC] 271.0 (2 min Phenomenex Luna C18 column, 4.6×30 mm eluting with 10-90% acetonitrile/H2O over 2 minutes containing 0.1% TFA; 5 mL/min, monitoring at 220 nm); IR vmax cm−1 neat: 2139 (N═C); NMR: 500 MHz 1H (CDCl3) δ ppm 5.94 (s, 1H), 7.12 (t, J=8.52 Hz, 2H), 7.25-7.29 (m, 1H), 7.30-7.35 (m, 3 H), 7.41 (s, 1H).

1. washLCMS: RT=1.37 min [M+H] 316.1 (2 min Phenomenex Luna C18 column, 4.6×30 mm eluting with 10-90% acetonitrile/H2O over 2 minutes containing 0.1% TFA; 5 mL/min, monitoring at 220 nm)
2. extractionextracted with Et2O (3×20 mL)
3. washThe combined organic layers were washed with sat. NaCl (20 mL)
4. dry with materialdried over anhydrous Na2SO4
5. filtrationthe filtered through basic alumina
6. concentrationThe filtrate was concentrated

ORD record

ord-5aebd275f3924da488ba828bab7b299c

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08304403B2