(4-Fluoro-2-methylphenyl)boronic acid → 3-(4-Methylthiophenyl)-4-(2-methyl-4-fluorophenyl)thiophene

Participants

Reaction Steps

The mono-substituted thiophene from Example 14 (1.8 mmol, 520 mg) was combined with the 2-methyl-4-fluorophenyl boronic acid (2 eq, 3.6 mmol, 562 mg) in 8.0 ml of toluene, 4.3 ml of 2 M sodium carbonate, 10 ml of ethanol and tetrakis(triphenylphosphine)-palladium(0)(1.0 g) and was stirred at reflux overnight. The reaction was concentrated in vacuo and the residue was partitioned between toluene and water. The toluene layer was dried (MgSO4) and reconcentrated in vacuo. The residue was purified via silica chromatography (Waters, LC-2000) in 97% hexane/ethyl acetate to give 3-(4-methylthiophenyl)-4-(2-methyl-4-fluorophenyl)thiophene (420 mg) as a semi-solid. NMR (CDCl3) δ 1.90(s, 3H), 2.43(s, 3H), 6.8–6.9(m, 2H), 7.05(q, J=8 Hz, 4H), 7.12–7.18(m, 2H), 7.33(d, J=2 Hz, 1H).

Provenance & Evidence