Process for the selective preparation of a 2-hydroxybenzoic acid and a 4-hydroxybenzaldehyde and derivatives thereof
US6245936A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1999 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Apr 12, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/255
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention concerns a process for the preparation of a 2-hydroxybenzoic acid and of a 4-hydroxybenzaldehyde and derivatives thereof from a mixture of two phenolic compounds, one carrying a formyl or hydroxymethyl group in the 2 position, and the other carrying a formyl or hydroxymethyl group in the 4 position. The invention also concerns the preparation of a 4-hydroxybenzaldehyde from said mixture. The invention more particularly concerns the preparation of 3-methoxy-4-hydroxybenzaldehyde and of 3-ethoxy4-hydroxybenzaldehyde, respectively known as "vanillin" and ethylvanillin". The process for the preparation of a 2-hydroxybenzoic acid and a 4-hydroxybenzaldehyde and derivatives thereof is characterised in that the formyl or hydroxymethyl group in the 2 position of compound (A) in a mixture of phenolic compounds, one (A) carrying a formyl or hydroxymethyl group in the 2 position, and the other (B) carrying a formyl or hydroxymethyl group in the 4 position, is selectively oxidised to a carboxy group and optionally a hydroxymethyl group of compound (B) in the 4 position is selectively oxidised to a formyl group, thus producing a mixture of a 2-hydroxybenzoic acid and a 4-h…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.