Methods of manufacturing derivatives of β-hydroxycarboxylic acids
Preparation of derivatives of β-hydroxycarboxylic acid, including β-hydroxycarboxylic acid esters, α,β-unsaturated carboxylic acid, esters of α,β-unsaturated carboxylic acid, and alkoxy derivatives.
1. A method for preparing a β-hydroxycarboxylic acid ester comprising reacting 3-hydroxypropionic acid, or salt thereof, with an alcohol in the presence of an esterification catalyst and the absence of solvent other than the alcohol under substantially anhydrous conditions at atmospheric pressure and a temperature less than reflux temperature to produce the ester.
2. A method according to claim 1 comprising preparing the ester at ambient temperature.
3. A method according to claim 1 wherein the alcohol contains between 1 and 7 carbon atoms, inclusive.
4. A method according to claim 1 wherein the esterification catalyst comprises an acid catalyst.
5. A method according to claim 4 wherein the acid catalyst comprises an acid resin catalyst.
6. The method of claim 1 , wherein the 3-hydroxypropionic acid is from a fermentation broth.
7. A method for preparing a β-hydroxycarboxylic acid ester comprising reacting 3-hydroxypropionic acid with an alcohol containing between 1 and 7 carbon atoms, inclusive, in the presence of an esterification catalyst in a water-immiscible extractant to produce a reaction mixture comprising the ester and the extractant.
8. A method according to claim 7 wherein the water-immiscible extractant is selected from the group consisting of amides, ethers, ketones, phosphorus esters, phosphine oxides, phosphine sulfides, alkyl sulfides, and combinations thereof.
9. A method for preparing a β-hydroxycarboxylic acid ester comprising:
(a) providing a fermentation broth comprising 3-hydroxypropionic acid, or salt thereof; (b) treating the broth with a water-immiscible extractant to form an extract comprising the 3-hydroxypropionic acid and the extractant; (c) combining the extract with an alcohol containing between 1 and 7 carbon atoms, inclusive, and an esterification catalyst; and (d) reacting the acid 3-hydroxypropionic acid with the alcohol in the presence of the extractant and the catalyst to produce the ester.
10. A method according to claim 7 or 9 wherein the esterification catalyst comprises an acid catalyst.
11. A method according to claim 10 wherein the acid catalyst comprises an acid resin catalyst.
12. A method according to claim 9 wherein the water-immiscible extractant is selected from the group consisting of amides, ethers, ketones, phosphorus esters, phosphine oxides, phosphine sulfides, alkyl sulfides, and combinations thereof.