Hydrochloric Acid → 2,6-Dichloro-4-nitrophenol

Participants

Reaction Steps

139 part of p-nitrophenol are suspended in 200 parts of water and the suspension is ground. The finely particulate suspension of p-nitrophenol so obtained is then added simultaneously with 260 parts of a 33 % solution of sodium chlorate to 1250 parts of 33 % hydrochloric acid. The simultaneous addition of educt and chlorinating agent is made at a temperature of 25° C. and such that the sodium chlorate is added over 240 minutes and the p-nitrophenol for 20 minutes longer over 260 minutes. The batch is subsequently allowed to react for 30 minutes and residual chlorine is expelled over a further 30 minutes. Any chlorine still remaining is destroyed with sodium bisulfite. The product is then isolated by filtration, washed until neutral and dried, affording 199.5 parts of 2,6-dichloro-4-nitrophenol in 99.7 % purity. The yield is 95.6 %; melting point: 119°-120° C. (lit.: 125° C.). Analysis by gas chromatography shows that the product has the same retention time as authentic material.

Provenance & Evidence