反应详情

To a suspension of 2-amino-5-nitro-4-trifluoromethyl-benzoic acid methyl ester (100 mg, 0.379 mmol) in dry toluene (1.5 mL) was added a solution of phosgene in toluene (20%, 1.5 mL) at −15° C. After warming to r.t., a stream of phosgene was introduced into the suspension and simultaneously heating was started. At reflux, the stream of phosgene was maintained for one hour, then replaced by a stream of argon for an additional hour. The toluene was distilled off leaving 2-isocyanato-5-nitro-4-trifluoromethyl-benzoic acid methyl ester (110 mg, 100%) 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. temperaturesimultaneously heating
2. temperatureAt reflux
3. waitreplaced by a stream of argon for an additional hour
4. distillationThe toluene was distilled off