Water → 4-Nitrodiphenylamine

Participants

Reaction Steps

The highest yields at minimum reaction temperature are attained from essentially anhydrous potassium formanilide, but small amounts of water have little effect. From a reaction mixture of 31.8 parts by weight (0.2 mole) of dry potassium formanilide, 24.2 parts by weight (0.154 mole) of para-nitrochlorobenzene, 9.3 parts by weight (0.077 mole) of formanilide and 25 parts by weight of xylene there is obtained after heating at 137°-149° C. for about 125 minutes a 92% yield of 4-nitrodiphenylamine and 97% conversion. The addition of 0.5% weight and 1.0% by weight of water respectively based on the potassium formanilide results in little or no reduction in yield and conversion. Addition of 1.0% by weight 45% potassium hydroxide improves the yield slightly. The innocuous effect of a little free water is to be contrasted with the adverse effect of bound water. Potassium formanilide forms a monohydrate which hydrolyzes rapidly when heated above temperatures of 85°-90° C. Replacing about half the formanilide with aniline in the foregoing procedure gives comparable result. The presence of aniline reduces the by-product carbon monoxide about 40% with formation of formanilide by mechanism imperfectly understood.

Provenance & Evidence