反应详情

To a solution of 3,5-dibromo-2-(difluoromethyl)pyridine (3.00 g, 10.5 mmol) in DMF (100 mL) was added K2CO3 (1.45 g, 10.5 mmol) at 0° C. Phenylmethanethiol (1.30 g, 10.5 mmol) in DMF (50 mL) was added through addition funnel over a period of 0.5 h and the reaction mixture was stirred at ambient temperature for 14 h. The reaction mixture was dissolved in EtOAc (300 mL) and washed with ice cold water (2×150 mL). The organic phase was separated, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by CombiFlash Isco (REDISEP®, SiO2, 12 g, 0-13% EtOAc/petroleum ether) to obtain a mixture of both regioisomers. Both regioisomers were separated by preparative HPLC (Condition B-16 described in general methods) to obtain 5-(benzylthio)-3-bromo-2-(difluoromethyl)pyridine (0.700 g, 20.3%) as a colorless liquid and 3-(benzylthio)-5-bromo-2-(difluoromethyl)pyridine (0.900 g, 26.1%) as a pale yellow liquid.

1. washwashed with ice cold water (2×150 mL)
2. customThe organic phase was separated
3. dry with materialdried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by CombiFlash Isco (REDISEP®, SiO2, 12 g, 0-13% EtOAc/petroleum ether)
7. customto obtain
8. additiona mixture of both regioisomers
9. customBoth regioisomers were separated by preparative HPLC (Condition B-16 described in general methods)