反应详情

A mixture of 0.44 g of N-methyl-6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide, 0.07 g of p-toluenesulfonic acid monohydrate, and 30 ml of toluene was heated at reflux for 10 hours. The solvent was removed by distillation, and the residue was purified by silica gel column chromatography (developing solution: CH2Cl2) to obtain 0.18 g of-N-methyl-6-cyano-2,2-dimethyl-2H-1-benzopyran-4-carbothioamide represented by formula shown below.

1. temperaturewas heated
2. temperatureat reflux for 10 hours
3. customThe solvent was removed by distillation
4. customthe residue was purified by silica gel column chromatography (developing solution: CH2Cl2)