Process for preparing glycidyl esters of branched monocarboxylic acids
View Patent ↗Accordingly, the invention relates to a process for the preparation of a glycidyl ester of a branched monocarboxylic acid by reacting an aliphatic monocarboxylic acid of the formula R 1 R 2 R 3 CCOOH, wherein R 1 , R 2 , and R 3 each independently represent an alkyl radical of normal or branched structure containing from 1 to 20 carbon atoms and an epoxyalkyl halide containing from 3 to 13 carbon atoms in the presence of a catalyst, wherein a greater than stoichiometric amount of epoxyalkyl halide is reacted with the acid (e.g., preferably in the molar ratio of epoxyalkyl halide to acid that is in the range of from 1.02:1 to 1.50:1) to form an intermediate reaction product comprising a halohydrin, the epoxyalkyl halide is added to the acid with appropriate cooling of the reactants and/or the reaction mixture to keep the temperature of the reaction mixture below 80° C., whereupon the epoxyalkyl halide and the acid are reacted at a temperature below 80° C. (preferably in the range of from 55 to 75° C.) for a time sufficient to reduce the amount of acid to no more than 2 wt % but no less than 0.1 wt % calculated on the initial amount of acid, optionally removing any excess epoxyalkyl halide from the reaction product prior to the ring closure reaction, subjecting the reaction product to a ring closure reaction (DHC) and optionally to one or more after treatments (ADHC) for removal of any remaining halo functionality.
1. A process for the preparation of a glycidyl ester of a branched monocarboxylic acid comprising reacting an aliphatic monocarboxylic acid of the formula R 1 R 2 R 3 CCOOH, wherein R 1 , R 2 , and R 3 each independently represent an alkyl radical of normal or branched structure containing from 1 to 20 carbon atoms and an epoxyalkyl halide containing from 3 to 13 carbon atoms in the presence of a catalyst, wherein
epoxyalkyl halide is reacted with the aliphatic monocarboxylic acid in a molar ratio of epoxyalkyl halide to aliphatic monocarboxylic acid of greater than 1 to 1.5 in a coupling reaction to form an intermediate reaction product comprising a halohydrin,
the epoxyalkyl halide is added to the aliphatic monocarboxylic acid with cooling of the reactants or the reaction mixture to keep the temperature of the reaction mixture from 55° C. to below 80° C., such that the epoxyalkyl halide and the aliphatic monocarboxylic acid are reacted at a temperature from 55° C. to 80° C. for a time sufficient to reduce the amount of aliphatic monocarboxylic acid from 0.1 wt % to 2 wt % calculated on the initial amount of aliphatic monocarboxylic acid,
retaining unreacted epoxyalkyl halide in the reaction product by the absence of distillation; and then
subjecting the reaction product to the ring closure reaction, wherein the catalyst is selected from the group consisting of alkali metal hydroxides, alkali metal carbonates, alkaline earth hydroxides, alkali metal, alkaline earth metal alcoholates, ammonium salts, and phosphonium salts.
2. The process of claim 1 , wherein a molar ratio of epoxyalkyl halide to aliphatic monocarboxylic acid is from 1.01 to 1.08.
3. The process of claim 2 , wherein the molar ratio of epoxyalkyl halide to aliphatic monocarboxylic acid is from 1.01 to 1.02.
4. The process of claim 1 , wherein unreacted epoxyalkyl halide is removed before the ring closure reaction.
5. The process of claim 1 , wherein the reaction temperature of the coupling reaction during and after the addition of the epoxyalkyl halide is from 55° C. to 75° C.
6. The process of claim 1 , wherein the reaction temperature of the coupling reaction during and after the addition of the epoxyalkyl halide is from 60° C. to 70° C.
7. The process of claim 1 , wherein the coupling reaction is continued until the amount of aliphatic monocarboxylic acid is from 0.3 wt % to 0.65 wt %.
8. The process of claim 1 , wherein the aliphatic monocarboxylic acid is an aliphatic tertiary alpha-branched monocarboxylic acid or a mixture thereof.
9. The process of claim 8 , wherein the aliphatic tertiary alpha-branched monocarboxylic acid has two alkyl groups linked to the carbon atom that is in the alpha position with respect to the carboxyl carbon atom.
10. The process of claim 9 , wherein the aliphatic tertiary alpha-branched monocarboxylic acid has from 4 to about 20 carbon atoms.
11. The process of claim 1 , wherein the epoxyalkyl halide is an epihalohydrin or a 2-methylepihalohydrin.
12. The process of claim 11 , wherein the epoxyalkyl halide has a chlorine or bromine atom.
13. The process of claim 1 , carried out in the absence of an additional solvent.
14. The process of claim 1 , wherein a homogeneous catalyst is used in the coupling reaction that does not require a solvent.
15. The process of claim 14 , wherein the catalyst comprises alkali metal hydroxides or alkali metal alkanoates.
16. The process of claim 15 , wherein the catalyst is selected from ammonium hydroxides or halides of the formula R′R″R′″R″″N + Y − , wherein R′, R″ and R′″ independently of each other may represent an alkyl group having from 1 to 16 carbon atoms wherein R″″ represents an alkyl group having from 1 to 16 carbon atoms, phenyl or benzyl, and wherein Y represents hydroxyl or halogen.
17. The process of claim 1 , wherein the process has no purification steps under pressure at the end of ring-closure reaction.
18. The process of claim 1 , further comprising removing epoxyalkylhalides as glycerine during the ring closure reaction.
19. The process of claim 16 , wherein the alkyl group may be is substituted with one or more hydroxyl groups.
20. The process of claim 9 , wherein the aliphatic tertiary alpha-branched monocarboxylic acid is a mixture of aliphatic tertiary alpha-branched monocarboxylic acids.