反应详情

To a mixture of 4.8 g of 3,4-dihydro-6-nitrospiro[2H-1-benzopyran-2,4'-tetrahydropyran]-3-one and 60 ml of dried N,N-dimethylformamide was added 1.65 g of methyl isothiocyanate under nitrogen stream. Then, 2.39 g of potassium tertiary butoxide was added therein with stirring under ice-cooling and the mixture was stirred for 1 hour and then stirred at 5° C. for 17 hours. Ice water was added to the reaction solution and it was washed with ether. A water layer was acidified to be hydrochloric acid and extracted with ether. An organic layer was washed with water and dried, and the solvent was distilled. The obtained residue was recrystallized by a mixed solvent of ethyl acetate and hexane to obtain 3.8 g of 3-hydroxy-N-methyl-6-nitrospiro-[2H-1-benzopyran-2,4'-tetrahydropyran]-4-carbothioamide with a melting point of 217°-218° C.

1. temperaturecooling
2. stirringthe mixture was stirred for 1 hour
3. stirringstirred at 5° C. for 17 hours
4. washwas washed with ether
5. extractionextracted with ether
6. washAn organic layer was washed with water
7. customdried
8. distillationthe solvent was distilled
9. customThe obtained residue was recrystallized by a mixed solvent of ethyl acetate and hexane