反应详情

温度

-30 °C

The title compound of Step A (9.0 g, 38 mmol) was dissolved in 50 mL of tetrahydrofuran and treated with methyl lithium (1.4 M in ether, 34 mL, 47 mmol) at a temperature of −70° C. The reaction mixture exothermed to −35° C. The mixture was stirred at −30° C. for 1.5 h and then treated with 1 mL of water and dichlorodicyanoquinone (9.44 g, 42 mmol). The mixture was stirred at 25° C. for 30 minutes and then partitioned twice between 100 mL of water and 100 mL of dichloromethane. The combined organics were washed with brine and dried over magnesium sulfate. The residue after evaporation was subjected to silica gel chromatography using hexanes/ethyl acetate (95:5) as eluent to give 9.02 g of the title compound of Step B as a white solid melting at 128-131° C. 1H NMR (CDCl3): δ2.31 (s, 3H), 2.56 (s, 3H), 7.71 (d, 2H), 8.49 (d, 2H), 8.53 (s, 1H).

1. customexothermed to −35° C
2. stirringThe mixture was stirred at 25° C. for 30 minutes
3. custompartitioned twice between 100 mL of water and 100 mL of dichloromethane
4. washThe combined organics were washed with brine
5. dry with materialdried over magnesium sulfate
6. customThe residue after evaporation