Process for the preparation of a substituted 4-hydroxybenzaldehyde
US5756853A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Oct 16, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/367
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The subject of the present invention is a process for the preparation of a 4-hydroxybenzaldehyde carrying at least one substituent in the position ortho to the OH group. It more particularly relates to the preparation of 3-methoxy-4-hydroxybenzaldehyde and of 3-ethoxy-4-hydroxybenzaldehyde. The process for the preparation of a substituted 4-hydroxybenzaldlehyde, substituted at least in the 3 position by an alkoxy group, is characterized in that it comprises subjecting a substituted phenol compound, substituted at least in the 2 position by an alkoxy group and in which the 4 and 6 positions are free, to a first stage of carboxylation in the 6 position, then to a stage of hydroxymethylation in the 4 position, followed by a stage of oxidation of the hydroxymethyl group to a formyl group, and finally to a last decarboxylation stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.