Method for preparing benzoic acid derivatives
US5214202A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Nov 6, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2602/10
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This invention relates to a synthesis method favorable for the industrial production of a benzoic acid derivative having a retinoid activity of the general formula: ##STR1## wherein the derivative can be obtained by a simple procedure in safety with high yield. Specifically, this invention relates to a synthesis method characterized in that only one vessel is needed for several reactions in the different steps of subjecting acetanilide as a starting material, which is readily available and safe to handle, to Friedel-Crafts reaction with 2,5-dimethyl-2,5-dichlorohexane; subjecting the thus obtained compound to acyl exchange reaction with monomethyl ester terephthalic chloride, followed by hydrolysis; and recrystallizing from a mixture of methanol and water. Moreover, the crystals in novel form obtained by the synthesis method of this invention are suitable for formulation, because the amount of solvents remaining therein after recrystallization is small and the grain size thereof is uniform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.