mixture with agitation the mixture was stirred at room temperature for 50 hours the mixture was filtered and washed with ethanol 260 ml u00d7 2 the solvent in the filtrate was removed under reduced pressure ethyl acetate 400 ml was added and the resulted mixture was washed with saturated brine 250 ml u00d7 2 the aqueous layer was extracted with ethyl acetate 100 ml u00d7 2 the organic phases were combined dried over anhydrous sodium sulfate and filtered the solvent in the filtrate was removed under the reduced pressure to give the title compound 109 g purity 98 yield 83 as a light yellow liquid 1 h nmr dmso d 6 400 mhz u03b47 64 dd j 2 hz 5 2 hz 1h 7 97 d j 1 6 hz 1h 8 54 d j 5 2 hz 1h 8 74 br 1h ms esi m z calcd for c 7 h 4 d 3 cln 2 o 173 found 174 m h 4 amino phenol 5 g 45 82 mmol 1 eq was dissolved in dichloromethane 40 ml at room temperature a solution of 1 chloro 4 isocyanato 2 trifluoromethyl benzene 10 7 g 48 11 mmol 1 05 eq in dichloromethane 40 ml was added dropwise the mixture was stirred at room temperature for 16 hours the mixture was filtered and washed with dichloromethane 10 ml u00d7 2.