Sulfuric Acid → 2,3,5,6-Tetrafluoroaniline

Participants

Reaction Conditions

Reaction Steps

2,3,5,6-Tetrafluoroaniline was produced from 4-amino-2,3,5,6-tetrafluorobenzonitrile. To be specific, in a 200 ml four-neck flask provided with a stirrer, a thermometer, a dropping funnel, and a water separating tube, 100 g of 60% sulfuric acid was placed and heated to 140° C. To the hot sulfuric acid, 36 g of the raw material, 4-amino-2,3,5,6-tetrafluorobenzonitrile (having a purity of 94% and containing 6% of 2-amino-3,4,5,6-tetrafluorobenzonitrile as an impurity) was added dropwise at a rate of 6 g/hr. The 2,3,5,6-tetrafluoroaniline which was formed by the reaction was expelled by azeotropy with water, guided into the water dropping tube, and separated from the water. The reaction was continued for six hours while the reaction vessel was supplied with the same amount of water as expelled by distillation. After the completion of the reaction, the conversion ratio of the raw material determined by gas chromatography was found to be 96 mol %. When the 2,3,5,6-tetrafluoroaniline expelled by distillation was analyzed, the purity was found to be 95.3% and the yield to be 82.5%.

Provenance & Evidence