反应详情

To a solution of ethyl 4-chloro-3,5-difluoropicolinate (1.5 g, 6.77 mmol) in toluene (25 mL) at −78° C. was added DIBAL (6.77 mL, 6.77 mmol) and the mixture was stirred for 4 hours. Then 3N HCl solution (20 mL) was added slowly and the mixture was allowed to warm to room temperature. After 1 hour, a saturated solution of NaHCO3 was added and the mixture was extracted with Et2O (2×150 mL). The combined organics were dried over Na2SO4 and evaporated to give 4-chloro-3,5-difluoropicolinaldehyde (1.15 g, 6.48 mmol, 96% yield) as a yellow liquid which was used in next step without further purification. MS [M+H] found 178.0.

1. waitAfter 1 hour
2. extractionthe mixture was extracted with Et2O (2×150 mL)
3. dry with materialThe combined organics were dried over Na2SO4
4. customevaporated