反应详情

温度

-50 °C

To a solution of 4[(4-methoxyphenyl)methyl]-6-(trifluoromethoxy)-2,3-dihydro-1,4-benzoxazine-2-carboxylic acid (290 mg, 0.76 mmol) in tetrahydrofuran (7 mL), under N2 atmosphere and cooled to −50° C., was added LDA (1.5 mL of 2 M, 3.03 mmol). The mixture was stirred for 2 h at −50° C. then treated with iodomethane (430 mg, 188 μL, 3.03 mmol). The mixture was allowed to warm to room temperature and stirred for 16 h. 30 mL water was added and the solution acidified to ˜pH 3 with 1 N HCl. The solution was extracted with ethyl acetate (3×10 mL) and the organic layer washed with brine, dried over Na2SO4, filtered and dried down to provide 4-[(4-methoxyphenyl)methyl]-2-methyl-6-(trifluoromethoxy)-3H-1,4-benzoxazine-2-carboxylic acid as an orange oil (300 mg, quantitative yield). LC/MS m/z 398.0 [M+H]+. 1H NMR (400.0 MHz, DMSO-d6) δ 13.11 (s, 1H), 7.21 (d, J=8.6 Hz, 2H), 6.88 (d, J=8.6 Hz, 2H), 6.80 (d, J=8.6 Hz, 1H), 6.60 (d, J=2.4 Hz, 1H), 6.51 (d, J=8.7 Hz, 1H), 4.45 (d, J=15.7 Hz, 1H), 4.30 (d, J=15.7 Hz, 1H), 3.73 (s, 3H), 3.67 (d, J=11.8 Hz, 1H), 3.15 (d, J=11.8 Hz, 1H), 1.48 (s, 3H).

1. temperatureto warm to room temperature
2. stirringstirred for 16 h
3. extractionThe solution was extracted with ethyl acetate (3×10 mL)
4. washthe organic layer washed with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customdried down