Lithium Hydroxide → 4-Methyl-5-(2-methyl-propenyl)-thiophene-2-carboxylic acid

반응식

C[O:2][C:3]([C:5]1[S:6][C:7]([CH:11]=[C:12]([CH3:14])[CH3:13])=[C:8]([CH3:10])[CH:9]=1)=[O:4].[Li+].[OH-]>CO.C(OCC)C>[CH3:10][C:8]1[CH:9]=[C:5]([C:3]([OH:4])=[O:2])[S:6][C:7]=1[CH:11]=[C:12]([CH3:14])[CH3:13]

참가 물질

실험 절차

A solution of 4-methyl-5-(2-methyl-propenyl)-thiophene-2-carboxylic acid methyl ester (4.08 g, 19.4 mmol) in methanol (33 mL) is treated with 2 N aq. LiOH solution (10 mL). The mixture is stirred at rt for 2 h, then at 45° C. for 3 h. The reaction mixture is diluted with diethyl ether. The org. layer is separated and extracted with water. The combined aq. phase is acidified with 1 M aq. HCl, and extracted twice with diethyl ether. The combined second org. extracts are dried over MgSO4, filtered and concentrated to give 4-methyl-5-(2-methyl-propenyl)-thiophene-2-carboxylic acid (3.05 g) as an off-white solid; LC-MS: tR=0.92 min, [M+1]+=196.98.