反应详情

To a suspension of 100 mg (0.379 mmol) of 2-amino-5-nitro-4-trifluoromethyl-benzoic acid methyl ester in 1.5 ml of dry toluene 1.5 ml of a 20% solution of phosgene in toluene are added at −15° C. After warming to room temperature, a stream of phosgene is introduced into the suspension and simultaneously heating is started. At reflux, the stream of phosgene is maintained for one hour, then replaced by a stream of argon for an additional hour. The toluene is distilled off leaving 110 mg (100%) of 2-isocyanato-5-nitro-4-trifluoromethyl-benzoic acid methyl ester as a beige solid. IR (CHCl3): 2260 cm−1 (s). 1H-NMR (CDCl3, 360 MHz): 4.05 (s, 3H); 7.55 (s, 1H); 8.65 (s, 1H).

1. additionare added at −15° C
2. temperaturesimultaneously heating
3. temperatureAt reflux
4. waitreplaced by a stream of argon for an additional hour
5. distillationThe toluene is distilled off