Process for the manufacture of alkylfluoroacrylate
The invention relates to a process for the manufacture of an alkylfluoroacrylate starting from alkylfluoroacetate and an oxalic acid ester, wherein an alkane liquid under the reaction conditions is applied as the solvent in one of the reaction steps.
1. A process for the manufacture of an alkylfluoroacrylate, comprising the following steps:
A. an alkylfluoroacetate with an ester of oxalic acid is reacted in the presence of sodium methoxide in methanol and a suitable solvent in a crossed Claisen condensation reaction resulting in a Claisen salt;
B. the Claisen salt obtained in step A is optionally filtered off and washed with a suitable solvent;
C. the Claisen salt obtained in step A or B is reacted with paraformaldehyde in a suitable solvent;
D. the alkylfluoroacrylate obtained in step C is isolated using a suitable solvent;
wherein the alkylfluoroacrylate is methylfluoroacrylate or ethylfluoroacrylate;
wherein the solvent in at least steps C and D and optionally in one of steps A or B is an alkane selected from a group consisting of pentane and hexane.
2. The process according to claim 1 , wherein the alkane is pentane.
3. The process according to claim 1 , wherein the ester of oxalic acid is dimethyloxalate.
4. The process according to claim 1 , wherein the solvent in step A is methyl-tert-butylether or pentane.
5. The process according to claim 1 , wherein alkylfluoroacrylate obtained after the reaction with paraformaldehyde is quenched with water before isolation.
6. The process according to claim 1 , wherein the isolation comprises a filtration and a distillation.