反应详情

A solution of 6-fluoro-3,4-dihydro-4-oxo-2H-1-benzopyran-2-carbonitrile (78.3 g, 0.41 mol)(obtained through the process as described in said Item (c) in 760 ml of concentrated hydrochloric acid was heated at reflux temperature for 50 minutes. After cooling the reaction solution, 700 ml of water and 1 liter of ethyl acetate were added to carry out an extraction. Resulting organic layer was evaporated in vacuo to dryness. To the residue, 700 ml of saturated sodium biscarbonate was added and stirred for 30 minutes. The aqueous basic solution was washed with 500 ml of ethyl acetate, acidified with 6N-hydrochloric acid and extracted with 1 liter of ethyl acetate. The organic layer was washed with water, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to give 76.9 g (89.3%) of the desired compound.

1. temperaturewas heated
2. temperatureat reflux temperature for 50 minutes
3. additionwere added
4. extractionan extraction
5. customResulting organic layer was evaporated in vacuo to dryness
6. additionTo the residue, 700 ml of saturated sodium biscarbonate was added
7. washThe aqueous basic solution was washed with 500 ml of ethyl acetate
8. extractionextracted with 1 liter of ethyl acetate
9. washThe organic layer was washed with water
10. dry with materialdried over anhydrous sodium sulfate
11. filtrationfiltered
12. customevaporated in vacuo