Process for the preparation of anthraquinone
US4220597A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1979 |
| Grant date | Sep 2, 1980 |
| Priority date | — |
| Expiry date | Jan 25, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/313
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process has been found for the preparation of anthraquinone by catalytic oxidation of naphthalene in the gas phase to provide a reaction product, obtained by quenching, cooling or quenching and cooling, containing naphthaquinone and phthalic anhydride, treating said reaction product directly with butadiene to provide tetrahydroanthraquinone, oxidation by means of molecular oxygen to the tetrahydroanthraquinone contained in this reaction product, to give anthraquinone, and separation of naphthalene, phthalic anhydride, anthraquinone and by-products by distillation, the gases produced in the quenching and/or cooling of the gases from the naphthalene oxidation and the gases from the oxidation of the tetrahydroanthraquinone to give anthraquinone being completely or partially recycled to the oxidation of naphthalene, in which a compound with an alkaline reaction is introduced between the reactor in which naphthalene is oxidized and the reactor in which the reaction with butadiene takes place, and/or into the gas streams which are recycled to the oxidation of naphthalene. The process of the invention reduces considerably the formation of higher-boiling products formed in the continuous…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.