反应详情

温度

0 °C

A solution of 5.30 g (21.32 mmol) of 3-chloro-2-fluoro-4-methylamino-5-nitro-benzoic acid in 53 mL of THF and 13.75 ml of MeOH is cooled to a temperature of 0° C. Then, 13.86 ml (27.72 mmol) of trimethylsilyl-diazomethane (2 M in diethylether) were added portion wise at a temperature of 0° C. The mixture is stirred 30 min at a temperature of 0° C. and 30 min at ambient temperature. The reaction mixture is evaporated with acetic acid in the trap. The yellow residue is titurated in diethyl ether and after decantation, 4.3 g (16.37 mmol, 77%) of a yellow solid is isolated. The Et2O phase is evaporated and 1.5 g of impure product is recovered. The crude product is used directly in the next step without purification. 1H-NMR (CDCl3, 300 MHz): ? ppm=3.30 (d, 3H), 3.95 (s, 3H), 7.80 (s br, 1H), 8.70 (d, 1H).

1. customThe reaction mixture is evaporated with acetic acid in the trap