MANUFACTURE OF HIGH PURITY TETRACHLORO-1,4- BENZOQUINONE

Highly pure tetrachloro-1,4-benzoquinone is prepared by the action of chlorine and hydrochloric acid on hydroquinone, characterised in that the 1.9- to 2.1-fold molar amount of gaseous chlorine is allowed to act, at temperatures from 5 to 15 DEG C, on 1 mole of hydroquinone in the 6- to 7-fold molar amount of 30% to 37% hydrochloric acid, the suspension obtained, which essentially contains the 2,5-dichlorohydroquinone, is then diluted with 2 to 3 parts of water relative to the hydroquinone employed, and first heated to a temperature of 20 to 30 DEG C, the 1.9- to 2.1-fold molar amount of chlorine gas is then passed in in an atmosphere of air and while increasing the temperature to 90 to 100 DEG C, while simultaneously diluting the mixture with 3.5 to 4.5 parts of water, relative to hydroquinone employed, and finally passing in, at temperatures from 100 to 115 DEG C, the 1- to 2-fold molar amount of gaseous chlorine, relative to hydroquinone employed.