BigPatents India

Two step preparation of hydroxy carboxylic acid (e.g. lactic acid) is achieved; Step 1) Carbonylating an enol ester (e.g. vinyl acetate) in presence of a hydroxyl compound (e.g. Methanol) using a palladium catalyst (e.g. PdCl2(PPh3)2), a O-, N- and/or P- containing ligand and a solvent, at 50-150°C/50-2000 psig to yield hydroxy ester (e.g. methyl lactate) and acetoxy ester (e.g. methyl-2-acetoxy propionate), separating and recycling the catalyst for carbonylation; Step 2) hydrolyzing the step 1 products to 2-hydroxy carboxylic acids (e.g. lactic acid) using acid catalysts (e.g. TsOH, aq HCl, resin) at 10-125°C, separating and recycling the catalyst for hydrolysis.