| abstract |
Process for the preparation of tetrachloro-1,4-benzoquinone of high purity by the action of chlorine and hydrochloric acid on hydroquinone, characterized in that 1 to 1 mol of hydroquinone in a 6 to 7-fold molar amount of 30 to 37% hydrochloric acid Allows 9- to 2.1-fold molar amount of gaseous chlorine to act at temperatures of 5 to 15 ° C., then the suspension obtained, essentially containing the 2,5-dichlorohydroquinone, is diluted with 2 to 3 parts of water, based on the hydroquinone used and first heated to a temperature of 20 to 30 ° C, then in an air atmosphere and increasing the temperature to 90 to 100 ° C, the 1.9 to 2.1 times molar amount of chlorine gas is introduced while diluting with 3.5 to 4.5 parts of water, based on the hydroquinone used, and finally the 1 to 2 times molar amount of gaseous chlorine, based on the hydroquinone used, at temperatures of 100 to 115 ° C. |