Process for the production of a dialkyl maleate
US4765869A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1987 |
| Grant date | Aug 23, 1988 |
| Priority date | — |
| Expiry date | Jul 31, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S203/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A continuous process is described for the production of a substantially acid free dialkyl maleate, for example diethyl maleate, from a feed stream containing a major amount of dialkyl maleate and a minor amount of the corresponding monoalkyl maleate. This comprises continuously distilling the feed stream in a primary distillation zone, which can comprise a single distillation column or a series of distillation columns connected in series, so as to give (i) a bottom fraction containing monoalkyl maleate and dialkyl maleate in admixture, (ii) a vaporous fraction comprising alkanol, and (iii) an intermediate fraction that is substantially free from alkanol and comprises a major proportion of diethyl maleate and a minor proportion of maleic anhydride. The intermediate fraction (iii) is redistilled in a secondary distillation zone to yield (i) an overhead fraction containing maleic anhydride and (ii) a bottom fraction containing substantially acid free dialkyl maleate. The vaporous stream can be condensed to recover alkanol for recycle to a dialkyl maleate production facility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.