One step synthesis for alkyl 2-fluoroacrylates
A process is provided that results in an alkyl haloacrylate that is produced by reaction of a dialkyl or diaryl halomalonate with an aldehyde, preferably formalin or paraformaldehyde, and a base catalyst to produce an intermediate that is not isolated and is heated to produce the alkyl haloacrylate. This synthesis can be one pot, meaning it reacts in the same vessel and/or reaction mixture and does not require isolation of the intermediate, and provides an improved yield. In particular, a process is provided that results in an alkyl 2-fluoroacrylate.
1. A process for preparing a fluoroacrylate compound comprising:
contacting a compound corresponding to the structure of Formula 1A with paraformaldehyde or formalin to form a reaction mixture of paraformaldehyde or formalin and a compound corresponding to the structure of Formula 1A
wherein each R 1 group is independently alkyl or aryl; and
heating the reaction mixture in the presence of a base to form a fluoroacrylate compound corresponding to the structure of Formula 2A
wherein conversion of the compound corresponding to the structure of Formula 1A to the compound corresponding to the structure of Formula 2A occurs in the same reaction mixture or wherein the overall yield of the compound corresponding to the structure of Formula 2A is at least 75% based on the number of moles of the compound corresponding to the structure of Formula 1A; and
wherein the base comprises lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, or a combination thereof.
2. The process of claim 1 , wherein the overall yield of the compound corresponding to the structure of Formula 2 is at least 90% based on the number of moles of the compound corresponding to the structure of Formula 1.
3. The process of claim 1 , wherein R 1 is methyl, ethyl, or propyl.
4. The process of claim 1 , wherein the base comprises cesium carbonate.
5. The process of claim 4 , wherein the reaction mixture is heated to a temperature of from about 110° C. to about 170° C.
6. The process of claim 5 , wherein the reaction mixture is heated for at least about 30 minutes.
7. The process of claim 1 , wherein the reaction mixture comprises one equivalent of the compound corresponding to the structure of Formula 1 or 1A and from about 1.1 to about 3 equivalents of paraformaldehyde.
8. The process of claim 1 , wherein the reaction mixture further comprises a solvent and the solvent comprises dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, ethylene glycol, polyethylene glycol, polypropylene glycol, ethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, quinoline, tetrahydroquinoline, N-methyl pyrrolidone, dimethyl imidazolidinone, sulfolane, glyme, diglyme, or a combination thereof.
9. The process of claim 8 , wherein the solvent comprises sulfolane.
10. A process for preparing patiromer calcium sorbitex comprising
preparing the fluoroacrylate of Formula 2A by the process of claim 1 ;
forming a polymerization reaction mixture comprising divinyl benzene, 1,7-octadiene, and the fluoroacrylate of Formula 2A to form crosslinked alkyl(2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer;
deprotecting the crosslinked alkyl(2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer to form crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer;
contacting the crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with a calcium salt to form crosslinked (calcium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer;
swelling the crosslinked (calcium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer and contacting with sorbitol to form patiromer calcium sorbitex.
11. The process of claim 10 , wherein the polymerization reaction mixture comprises divinyl benzene, 1,7-octadiene, the fluoroacrylate of Formula 2A, and a polymerization initiator.
12. The process of claim 11 , wherein deprotecting the crosslinked alkyl(2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer to form crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer comprises hydrolyzing the crosslinked alkyl(2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer by contacting the crosslinked alkyl(2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with a strong base.
13. The process of claim 12 , wherein contacting the crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with the calcium salt to form crosslinked (calcium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer comprises slurrying the crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with the calcium salt.
14. The process of claim 13 , wherein contacting the crosslinked (2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with the calcium salt to form crosslinked (calcium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer comprises slurrying the crosslinked (sodium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer with the calcium salt.
15. The process of claim 14 , wherein the swelling of the crosslinked (calcium 2-fluoroacrylate)-divinylbenzene-1,7-octadiene polymer comprises slurrying the polymer in a solution comprising sorbitol.