Patent ID: 9056848
Filing Date: 2015-06-16
Classification: C07D

Abstract:
1. A process for preparing a sodium or potassium salt of 4-hydroxy-2-oxo-2,5-dihydrofuran-3-carboxylic ester of formula (I) in which Z is sodium or potassium, and R comprising: (i): reacting a symmetric malonic ester of formula (II) with potassium hydroxide to give the corresponding malonic ester potassium salt of formula (III) in which, in formulae (II) and (III), R in a solvent; (ii): reacting a malonic ester potassium salt of formula (III) with a chloroacetic ester of formula (IV) in which R to give a compound of formula (V) in which R R (iii): reacting a compound of formula (V) with a sodium or potassium alkoxide of formula ZOR R Z is sodium or potassium, wherein after addition of the chloroacetic ester in (ii), the reaction mixture is subjected to azeotropic dewatering,