Synthesis of methylene malonates using rapid recovery in the presence of a heat transfer agent
The present invention provides a method of making a methylene malonate monomer that includes the steps of reacting a malonic acid ester with a source of formaldehyde optionally in the presence of an acidic or basic catalyst and optionally in the presence of an acidic or non-acidic solvent to form reaction complex. The reaction is optionally performed in the presence of or contacted with an energy transfer means such as a heat transfer agent, a heat transfer surface, a source of radiation or a laser such that reaction complex is substantially vaporized to produce a vapor phase comprising methylene malonate monomer which may be isolated. The present invention further provides methylene malonate monomers prepared by the method of the invention, as well as compositions and products formed from the methylene malonate monomers, including monomer-based products (e.g., inks, adhesives, coatings, sealants or reactive molding) and polymer-based products (e.g., fibers, films, sheets, medical polymers, composite polymers and surfactants).
1. A method of making a methylene malonate monomer comprising:
a) reacting a malonic acid ester with a source of formaldehyde; optionally in the presence of an acidic or basic catalyst; and in the absence of solvent, to form a reaction complex;
b) contacting the reaction complex or a portion thereof with an energy transfer means at a temperature of about 130° to about 300° to produce a vapor phase comprising methylene malonate monomer wherein the reaction complex or the portion thereof is substantially vaporized in less than 1 minute; and
c) isolating the methylene malonate monomer from the vapor phase.
2. The method according to claim 1 , wherein the reaction complex or the portion thereof is substantially vaporized in less than 10 seconds.
3. The method according to claim 1 , wherein the reaction complex of the portion thereof is substantially vaporized prior to the formation of latent acid forming impurities or irreversible complex impurities.
4. The method according to claim 1 , comprising repeating steps (b) and (c) on additional portions of the reaction complex, wherein each portion of the reaction complex is substantially vaporized in step (b) prior to the contacting of another portion of the reaction complex with the energy transfer means.
5. The method according to claim 1 , wherein the reaction complex is vaporized continuously upon formation in step (a).
6. The method according to claim 1 , wherein the energy transfer means is at least one member of the group consisting of: a heat exchanger, a laser, a source of radiation and microwave radiation.
7. The method of according to claim 1 wherein the energy transfer means comprises a heated inert gas, one or more metal articles, one or more glass articles, one or more porcelain articles, sand, silica, silicone oil, mineral oil, a petroleum-based heat transfer oil, a synthetic chemical-based heat transfer oil, or a pre-formed portion of the reaction complex.
8. The method according to claim 1 , wherein in (a) reacting the malonic acid ester with the source of formaldehyde is performed at about 60° C. to about 130° C.
9. The method according to claim 1 , wherein in (c) isolating the methylene malonate monomer is achieved by a separation technique selected from condensation, simple distillation, fractional distillation, flash distillation, steam distillation, vacuum distillation, short path distillation, thin-film distillation, reactive distillation, pervaporation, extractive evaporation, flash evaporation, rotary evaporation, gas chromatography or liquid chromatography.
10. The method according to 1 further comprising the step of (d) redistilling the methylene malonate monomer under reduced pressure within about 60 minutes of isolation.
11. The method according to 1 further comprising the step of inactivating the catalyst prior to producing the vapor phase.
12. The method according to 1 further comprising the step of minimizing recovery of volatile latent acid forming impurities.
13. The method according to claim 1 wherein the reacting step (a) is performed in the presence of a basic catalyst selected from potassium acetate, sodium acetate, zinc acetate, zinc diacetate dehydrate, aluminum acetate, calcium acetate, magnesium acetate, magnesium oxide, copper acetate, lithium acetate, aluminum oxide, zinc oxide or any combination thereof.
14. The method according to claim 1 wherein the malonic acid ester has the formula:
R—O—C(O)—CH2-C(O)—O—R′
wherein R and R′ are independently C 1 -C 15 alkyl, C 2 -C 15 alkenyl, halo-(C 1 -C 15 alkyl), C 3 -C 6 cycloalkyl, halo-(C 3 -C 6 cycloalkyl), heterocyclyl, heterocyclyl-(C 1 -C 15 alkyl), aryl-(C 1 -C 15 alkyl), heteroaryl or heteroaryl-(C 1 -C 15 alkyl), or alkoxy-(C 1 -C 15 alkyl), each of which may be optionally substituted by C 1 -C 15 alkyl, halo-(C 1 -C 15 alkyl), C 3 -C 6 cycloalkyl, halo-(C 3 -C 6 cycloalkyl), heterocyclyl, heterocyclyl-(C 1 -C 15 alkyl), aryl, aryl-(C 1 -C 15 alkyl), heteroaryl, C 1 -C 15 alkoxy, C 1 -C 15 alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester; or
wherein R and R′ are taken together with the atoms to which they are bound to form a 5-7 membered heterocyclic ring which may be optionally substituted by C 1 -C 15 alkyl, halo-C 1 -C 15 alkyl), C 3 -C 6 cycloalkyl, halo-(C 3 -C 6 cycloalkyl), heterocyclyl, heterocyclyl-(C 1 -C 15 alkyl), aryl, aryl-(C 1 -C 15 alkyl), heteroaryl, C 1 -C 15 alkoxy, C 1 -C 15 alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester.
15. The method according to claim 1 wherein the reaction complex comprises one or more oligomeric complexes capable of forming the methylene malonate monomer as a result of conducting step (b).
16. The method according to claim 15 wherein the one or more oligomeric complexes independently comprise between 2 and 12 units of methylene malonate monomer.
17. The method according to claim 15 wherein the oligomeric complex comprises at least one of the following physiochemical properties:
(b) a MALDI-TOF analysis spectrum comprising peaks at: 131, 153, 176, 192, 194, 470, 472, 675, and 758; or
(c) a proton NMR spectrum in CDCl 3 at 400 MHz comprising the following peaks: a singlet at 4.66 ppm and narrow peaks located between 4.32-3.8 ppm.
18. The method according to claim 15 wherein the oligomeric complex results in a weight loss of less than 20% below 218° C. as measured by thermogravimetric analysis.