反应详情

A mixture of 0.14 g of N-ethyl-6-cyano-2,2-dimethyl-2H-1-benzopyran-4-carbamide, 3.45 g of Lawesson's reagent, and 10 ml of benzene was refluxed for 1 hour. Any insoluble matter was collected by filtration with suction and washed with methylene chloride. The mother liquor and the washing were combined, and the solvent was removed therefrom by distillation. The residue was purified by silica gel column chromatography (developing solution: CH2Cl2) to obtain 0.12 g of N-ethyl-6-cyano-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide represented by formula shown below.

1. temperaturewas refluxed for 1 hour
2. filtrationAny insoluble matter was collected by filtration with suction
3. washwashed with methylene chloride
4. customthe solvent was removed
5. distillationby distillation
6. customThe residue was purified by silica gel column chromatography (developing solution: CH2Cl2)