Synthesis of (meth) acrylic anhydride by transanhydrization
US9969670B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2015 |
| Grant date | May 15, 2018 |
| Priority date | — |
| Expiry date | Jan 20, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/56
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a method for producing a (meth)acrylic anhydride A-C(═O)—O—(O═)C-A, comprising the following steps: a) a step of reacting an anhydride B—C(═O)—O—(O═)C—B with an acid A-COOH, resulting in the formation of mixed anhydride A-C(═O)—O—(O═)C—B and acid B—COOH; and b) a step of reacting the mixed anhydride with A-COOH, resulting in the (meth)acrylic anhydride. According to the invention, reaction steps (a) and (b) are carried out in the presence of hydrated triflic acid, and the anhydride A-C(═O)—O—(O═)C-A is isolated from the reaction medium produced in step (b) as follows: e1) heavy compounds having a volatility less than or equal to that of the anhydride A-C(═O)—O—(O═)C-A are separated from the reaction medium, said compounds including the anhydride and the hydrated triflic acid; e2) the anhydride is separated from the heavy compounds by difference in volatility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.