反应详情

A mixture of 0.93 g of 4-cyano-2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran, 20 ml of acetic acid, 10 ml of water and 10 ml of concentrated sulfuric acid was refluxed with heating for 4.5 hours. When the reaction mixture was poured into ice water, crystals were separated out. Said crystals were dissolved with a sodium hydrogen carbonate solution and washed with methylene chloride. A water layer was acidified to be hydrochloric acid and extracted with methylene chloride. An organic layer was washed with water and dried, and the solvent was distilled to obtain 0.83 g of 2,2-bis(fluoromethyl)-6-nitro-2H-1-benzopyran-4-carboxylic acid with a melting point of 171°-172° C.

1. temperaturewas refluxed
2. temperaturewith heating for 4.5 hours
3. customwere separated out
4. dissolutionwere dissolved with a sodium hydrogen carbonate solution
5. washwashed with methylene chloride
6. extractionextracted with methylene chloride
7. washAn organic layer was washed with water
8. customdried
9. distillationthe solvent was distilled