反应详情

Trimethylsilyldiazomethane (2.0 M solution in hexanes, 37 mL, 74 mmol) was added slowly to a suspension of 4-(4-bromo-2-chloro-phenylamino)-5,6-dichloronicotinic acid (25) (14.67 g, 37 mmol). After the addition was complete the resulting slurry was diluted with hexanes (600 mL) and the solids isolated by filtration washing with hexanes. The desired product was isolated as an off-white solid (10.06 g). The hexanes washes were concentrated and the solids passed through a plug of silica gel eluting with dichloromethane. Concentration of the product-containing fractions provided an additional 3.83 g desired product (26) for a total of 13.89 g (91%). MS (APCI+) m/z 409, 411, 413 (M+; Cl, Br pattern) detected.

1. additionAfter the addition
2. customthe solids isolated by filtration
3. washwashing with hexanes