反应详情

To a cooled (0° C.) solution of 5-bromo-2-(methyloxy)-3-pyridinamine (13.7 g, 67.5 mmol) in pyridine (200 ml) was added slowly 2,4-difluorobenzenesulfonyl chloride (14.37 g, 67.6 mmol) over 15 min (reaction became heterogeneous). The ice bath was removed and the reaction was stirred at ambient temperature for 16 h. Most of the pyridine was removed in vacuo and the residue diluted with water (500 mL). The solids were filtered off and washed with copious amounts of water to give 21 g of crude desired product. More solid appeared in the mother liquor and was filtered and washed with water to give an additional 1.5 g of desired material. The two batches were combined, triturated with 70 ml of methylene chloride, and dried in a vacuum oven at 50° C. to give the title compound (15 g).

1. custom(reaction became heterogeneous)
2. customThe ice bath was removed
3. customMost of the pyridine was removed in vacuo
4. additionthe residue diluted with water (500 mL)
5. filtrationThe solids were filtered off
6. washwashed with copious amounts of water
7. customto give 21 g of crude desired product
8. filtrationwas filtered
9. washwashed with water