Triethylamine → 4-Chloro-5-cyclopentyloxy-2-fluorophenylisocyanate

Participants

Reaction Conditions

Reaction Steps

The mixture of trichloromethyl chloroformate (530 ml, 4.4 mol) and toluene (4 liters) were put in a 10-liter three-neck flask as equipped with a stirrer, a dropping funnel, and a reflux condenser, and cooled to 0° C. To the solution was dropwise added a toluene solution (1 liter) containing 2-fluoro-4-chloro-5-cyclopentyloxyaniline (1.0 kg, 2.86 mol) and triethylamine (20 ml) over a period of 8 hours. After addition, the reaction solution was stirred under heat at about 100° C. After reaction, toluene was removed by distillation, and the impurities as precipitated out were removed by filtration. As a result, 2-fluoro-4-chloro-5-cyclopentyloxyphenylisocyanate was obtained almost quantitatively. Spectral data and other data of the product are those as shown in Example 24.

Provenance & Evidence