反应详情

温度

45 °C

To 3-Bromo-6H-benzo[c]chromene-8-carboxylic acid (0.5 mmol) was added a solution of oxalyl chloride in DCM (2.0 N, 5 ml, 10 mmol). The mixture was heated at 45° C. for 2 hours and cooled to 25° C. Excess reagents and solvent were removed under reduced pressure and co-evaporated with toluene. To the solution of above residue in DCM (5 ml) at 0° C. trimethylsilyldiazomethane (2.0 N, 0.75 ml, 1.5 mmol) was added dropwise. The mixture was stirred at 25° C. for 12 hours and was concentrated. The residue was dissolved in EtOAc and was cooled to 0° C. To above solution HBr/HOAc (0.28 ml, 1.5 mmol) was added dropwise. The mixture was stirred at 25° C. for 1 hour. Solid sodium bicarbonate was added and the mixture was stirred for 30 minutes. The mixture was diluted with EtOAc, and was washed with water and brine and was dried with Na2SO4. Concentration gave 2-Bromo-1-(3-bromo-6H-benzo[c]chromen-8-yl)-ethanone, which was used for next step without purification.

1. temperaturecooled to 25° C
2. customExcess reagents and solvent were removed under reduced pressure and co-evaporated with toluene
3. concentrationwas concentrated
4. dissolutionThe residue was dissolved in EtOAc
5. temperaturewas cooled to 0° C
6. stirringThe mixture was stirred at 25° C. for 1 hour
7. stirringthe mixture was stirred for 30 minutes
8. washwas washed with water and brine
9. dry with materialwas dried with Na2SO4
10. concentrationConcentration