反应详情

To a mixture of 120 mg of N-methyl-6-nitro-spiro[2H-1benzopyran-2,1'-cyclohexane]-4-carbothioamide, 150 μl of iodoethane, and 3 ml of dried tetrahydrofuran was added 23 mg of sodium hydride (60%) with stirring and cooling with ice followed by refluxlng for 2 hours. After cooling to room temperature, 80 mg of cyanamide and 17 mg of sodium hydride (60%) were added thereto, followed by refluxing for 4 hours. Ice-water was added thereto, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and dried, and the solvent was removed by distillation. The residue was purified by silica gel column chromatography (developing solution: ethyl acetate:hexane=2:3) recrystallized from a mixed solvent of ethyl acetate and hexane to obtain 90 mg of N-cyano-N'-methyl-6-nitrospiro[2H-1-benzopyran-2,1'-cyclohexane]-4-carboxamidine having formula shown below.

1. temperaturecooling with ice
2. temperatureby refluxing for 4 hours
3. extractionthe mixture was extracted with ethyl acetate
4. washThe organic layer was washed with water
5. customdried
6. customthe solvent was removed by distillation
7. customThe residue was purified by silica gel column chromatography (developing solution: ethyl acetate:hexane=2:3)
8. customrecrystallized from a mixed solvent of ethyl acetate and hexane