2-Methyl-2-butene → 3-Methyl-5-phenylthiophene-2-carboxylic acid

Participants

Reaction Steps

To a stirred solution of 3-methyl-5-phenyl-thiophene-2-carbaldehyde (0.200 g, 0.99 mmol) and 2-methyl-2-butene (2.77 g, 0.040 mol) in dimethylformamide (4 ml) at 0° C. was added NaClO2 (0.894 g, 9.89 mmol) and NaH2PO4 (1.09 g, 7.91 mmol) in water (5 ml). The solution was allowed to warm to room temperature and stirred for 18 hours. The solvent was removed at reduced pressure and the residue partitioned between dichloromethane (10 ml) and 1N HCl solution (10 ml). The organic was separated, the aqueous layer extracted with dichloromethane (2×5 ml). The combined organic layers were dried (MgSO4) and the solvent removed at reduced pressure to give a yellow oil. Purification by flash column chromatography 50% ethyl acetate/petrol 40-60° C.) gave the sub-title compound as a white solid (0.14 g, 69% yield): 1H NMR (400 MHz, CDCl3) δH 2.65 (3H, s), 7.25 (1H, s) 7.35-7.80 (5H, s).

Provenance & Evidence