反应详情

温度

0 °C

To a solution of thiophene (1.69 g) in anhydrous tetrahydrofuran (20 ml) is added dropwise a 1.6 M n-butyl lithium/n-hexane solution (11.4 ml) at 0° C. under argon atmosphere over a period of 30 minutes. To the mixture is added dropwise and gradually a solution of 5-(4-methylphenyl)-4,6-dichloropyrimidine (4.0 g) in anhydrous tetrahydrofuran (5 ml) at -60° C. The mixture is warmed to 0° C., and stirred for 1.5 hour. After the reaction is complete, to the mixture are added acetic acid (1.5 g) and water (0.25 g), and further added thereto a solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (5.70 g) in tetrahydrofuran (5 ml), and the mixture is stirred at 0° C. for one hour. The mixture is treated with an active charcoal, and extracted with a mixture of ethyl acetate and aqueous citric acid solution. The extract is washed, dried and evaporated to remove the solvent. The residue is purified by silica gel column chromatography (solvent; n-hexane/ethyl acetate=50:1) to give 5-(4-methylphenyl)-4,6-dichloro-2-(2-thienyl)pyrimidine (2.64 g) as powder.

1. additionTo the mixture is added dropwise
2. customat -60° C
3. additionfurther added
4. extractionextracted with a mixture of ethyl acetate and aqueous citric acid solution
5. washThe extract is washed
6. customdried
7. customevaporated
8. customto remove the solvent
9. customThe residue is purified by silica gel column chromatography (solvent; n-hexane/ethyl acetate=50:1)