反应详情

A solution of 2-bromopyridine (1.51 g, 9.58 mmol) in dry tetrahydrofuran (20 mL) was stirred under nitrogen at −78° C. and 2.5M n-butyllithium in hexanes (3.8 mL, 9.5 mmol) was added at such a rate that the temperature did not exceed −70° C. Stirring was continued at −78° C. for 30 min. when a solution of 9 (2.1 g, 6.1 mmol) in tetrahydrofuran (15 mL) was added at such a rate that the temperature did not exceed −65° C. Stirring was continued at −78° C. for 20 min., then for 2 hr at room temperature. The reaction mixture was poured on saturated ammonium chloride (150 mL) and extracted with ethyl acetate (200 mL). The organic extract was washed with water (2×100 mL), dried over sodium sulfate and stripped. The crude 10 was used as such in the next step.

1. customdid not exceed −70° C
2. customdid not exceed −65° C
3. stirringStirring
4. waitwas continued at −78° C. for 20 min.
5. waitfor 2 hr at room temperature
6. extractionextracted with ethyl acetate (200 mL)
7. extractionThe organic extract
8. washwas washed with water (2×100 mL)
9. dry with materialdried over sodium sulfate