4-METHYL-5-PHENYL-THIOPHENE-2-CARBOXYLIC ACID synthesis

Yield:40133-12-8 25%

Reaction Conditions:

Stage #1: ethyl 4-methyl-5-phenylthiophene-2-carboxylate;4-methyl-5-phenyl-thiophene-2-carboxylic acid methyl esterwith methanol;sodium hydroxide;water at 20; for 0.5 h;
Stage #2: with hydrogenchloride;water pH=4;

Steps:

7.h.ii

(ii) 4-Methyl-5-phenyl-thiophene-2-carboxylic acid; To a solution of 4-methyl-5-phenyl-thiophene-2-carboxylic acid (methyl and ethyl) ester (106 mg,-0. 45 mmol) in MeOH (5 ml) was added 1M NaOH (5 ml) and the resulting solution was stirred for 30 min at room temperature. The MeOH was then removed in vacuo. DCM (20 ml) and water (20 ml) were added and the aqueous layer extracted with DCM (2 x 20 ml). The aqueous layer was acidified with 2M HCl until a white precipitate formed. This was then extracted with EtOAc (3 x 20 ml). The combined organic layers were washed with brine (20 ml), dried (Na2SO4), filtered and the solvent removed in vacuo to give the title compound. Yield: 25 mg, 25%; LC/MS tr 1. 42 min; MS (ES+) m/z 260 (M+H+ MeCN)

References:

WO2005/80367,2005,A1 Location in patent:Page/Page column 103-104