4-(carboxymethyl)thiophene-3-carboxylic acid synthesis

Yield:57279-54-6 72%

Reaction Conditions:

Stage #1: 4-(2-ethoxy-2-oxoethyl)thiophene-3-carboxylic acidwith water;potassium hydroxide at 0 - 20;
Stage #2: with hydrogenchloride in water at 0;

Steps:

5

4-(Carboxymethy)thiophene-3-carboxylic acid (39): To a suspension of ester (38) (5.17 gm, 24 mmol) in water (20 ml) was added KOH (4.9 gm) at 0 ⁰C. After the reaction mixture became homogeneous, the cold bath was removed and the reaction was stirred at rt for 16 hr. Reaction mixture was then acidified with HCl (12 M aqueous solution) at 0 ⁰C. The solid precipitated out was filtered, washed with water and dried under vacuum to give diacid (39) (3.23 gm, 72%).

References:

WO2010/77663,2010,A2 Location in patent:Page/Page column 78; 90