反应详情

温度

-78 °C

To a mixture of THF (300 mL) and LDA (100 mL, 20.1 mmol) at −20° C. was added Bu3SnH (50 mL, 17.4 mmol) dropwise and stirred for 15 min. The reaction mixture was cooled to −78° C. and treated with 2,4-dichloro pyrimidine (20 g, 134 mmol) portionwise. The reaction mixture was stirred at −78° C. for 5 h with constant stirring under argon atmosphere. The cooling bath was removed and the reaction mixture was warmed up to 0° C. within 30 min. The resulting mixture was poured into 10% NH4Cl aqueous solution, and extracted the compound with Et2O. The organic layer was washed with brine, dried with Na2SO4, filtered, and evaporated. The residue was purified by column chromatography (1% EtOAc: 99% n-Hexane) to obtain 2-chloro-4-tributylstannanyl-pyrimidine 20a (3 g, 5.5% yield) as a pale yellow color syrup and 4-chloro-2-tributylstannanyl-pyrimidine 24a (13 g, 24% yield) as a pale yellow color syrup. Compound 24a: MS (ESI, pos. ion) m/z: 405.3 (M+1).

1. stirringThe reaction mixture was stirred at −78° C. for 5 h
2. stirringwith constant stirring under argon atmosphere
3. customThe cooling bath was removed
4. temperaturethe reaction mixture was warmed up to 0° C. within 30 min
5. additionThe resulting mixture was poured into 10% NH4Cl aqueous solution
6. extractionextracted the compound with Et2O
7. washThe organic layer was washed with brine
8. dry with materialdried with Na2SO4
9. filtrationfiltered
10. customevaporated
11. customThe residue was purified by column chromatography (1% EtOAc: 99% n-Hexane)