The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 1996
Filed:
Feb. 22, 1995
Otto Arndt, Hofheim, DE;
Wolfgang Tronich, Eppstein, DE;
Hoechst A G, , DE;
Abstract
The invention relates to a process for the preparation of tetrachloro-1,4-benzoquinone of high purity by the action of chlorine and concentrated hydrochloric acid on hydroquinone, which involves introducing a portion of the hydroquinone to be employed into initially introduced hydrochloric acid containing catalytic amounts of iron(III) ions and an anionic dispersant, introducing chlorine gas into this solution at a temperature from 20.degree. to 107.degree. C., then adding the residual quantity of hydroquinone as a solid or in solution, raising the temperature to from 80.degree. to 107.degree. C. while continuing to pass in gaseous chlorine, adding, after the introduction of gaseous chlorine has ended, a relatively high-boiling organic solvent which is not miscible with hydrochloric acid, and subsequently subjecting the reaction mixture to thermal aftertreatment.