Patent ID: 7754916
Filing Date: 2010-07-13
Classification: C07C

Abstract:
1. A process for preparing an unsaturated carboxylic acid, and esters thereof, from an ammonium salt of a beta-hydroxypropionic acid, said process comprising: a) providing an aqueous solution comprising the ammonium salt of a beta-hydroxypropionic acid; b) converting the ammonium salt of a beta-hydroxypropionic acid to a corresponding beta-hydroxypropionic acid and ammonium cation in aqueous solution; and c) separating the ammonium cation from the aqueous solution, leaving the beta-hydroxypropionic acid in aqueous solution; wherein said converting and separating steps b) and c) are accomplished by a technique selected from the group consisting of: (1) adding a solution comprising a hydrophobic acid and, optionally, an organic solvent, to the aqueous solution, wherein the hydrophobic acid comprises a proton and a conjugate base, is immiscible in water, is capable of forming an ammonium salt which is also immiscible in water, and has an acid dissociation constant (pK (2) contacting the aqueous solution comprising the ammonium salt of beta-hydroxypropionic acid with an acid ion exchange resin having an acid dissociation constant (pK