Process for drying hydrogen fluoride-carboxylic acid mixtures
US4894482A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1988 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Dec 6, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C45/83
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is provided for removing water from a mixture of hydrogen fluoride (HF), a carboxylic acid, e.g., acetic acid, and water by extractive distillation in the presence of a Lewis base as solvent, which does not azeotrope with water, forms bonds with the HF and carboxylic acid which can be broken by heat and has a boiling point at atmospheric pressure at least about 20.degree. C. above that of the carboxylic acid, e.g., N-methyl-2-pyrrolidone, and taking off an overhead vapor comprising a major proportion of the water in said mixture. The extractive distillation may be advantageously integrated in an overall process with the production of an aromatic ketone, e.g., 4-hydroxyacetophone, by the Friedel-Crafts acylation of an aromatic compound, e.g., phenol, with the carboxylic acid, using HF as catalyst, to produce a product mixture comprising the aromatic ketone, HF, carboxylic acid and water, and the removal of aromatic ketone from the product mixture by means of a solvent assisted distillation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.