Preparation of tetrakis [3-(3,5-di-tert-butyl-4-hydroxy phenyl) propionyl oxymethyl] methane
US7601862B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 2004 |
| Grant date | Oct 13, 2009 |
| Priority date | — |
| Expiry date | Oct 27, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C67/03
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A transesterification process for the preparation of tetrakis [3-(3,5-di-tert-butyl-4-hydroxy phenyl)propionyl oxymethyl] methane by the reaction of methyl-(3,5-di-tert-butyl-4-hydroxy phenyl)propionate ester with pentaerythritol wherein the reaction takes place in the presence of an ester exchange catalyst combination consisting of (a) at least one basic or neutral catalyst and (b) at least one metal compound capable of behaving as a Lewis acid and wherein the reaction is conducted through a first stage in which only basic or neutral catalyst is present in the reaction mixture followed by a second stage which commences with the addition of Lewis acid catalyst to the reaction mixture when the amount of di-substituted intermediate product contained within the reaction mixture is less than 20 area % analyzed by HPLC.The preferred basic catalysts are lithium hydroxide and lithium hydroxide monohydrate.The preferred Lewis acid catalyst is zinc octanoate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.