Process for preparing and recovering 4,4'-dihydroxy-alpha-alkylstilbene or 4,4'-dihydroxy-alpha, alpha'dialkylstilbene
US5723693A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 13, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | Sep 13, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C37/84
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing a 4,4'-dihydroxy-alpha-alkylstilbene or 4,4'-dihydroxy-alpha,alpha'-dialkylstilbene which includes the steps of (A) reacting at a temperature of from -20.degree. C. to 20.degree. C. a mixture of: (1) at least one alpha-haloketone; (2) at least one compound containing one phenolic hydroxyl group or aromatic alkoxy group per molecule such that the mole ratio of phenolic hydroxyl group-containing or aromatic alkoxy group-containing compound(s):alpha-haloketone(s) is at least 0.1:1; and (3) either (a) at least one strong protonic acid or (b) at least one Lewis acid, or (c) any combination thereof; thereby forming a reaction product containing at least one halogen-containing bisphenol compound which, upon being dehydrohalogenated, forms a 4,4'-dihydroxy-alpha-alkylstilbene or 4,4'-dihydroxy-alpha, alpha'-dialkylstilbene; (B) reducing the acid content of the product resulting from step (A) to less than 10,000 ppm; (C) dehydrohalogenating the product obtained from step (B), thereby forming a dehydrohalogenated product containing 4,4'-dihydroxy-alpha-alkylstilbene or 4,4'-dihydroxy-alpha,alpha'-dialkylstilbene; (D) adding water to the product of step (C) in amounts …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.