Pivalic acid → 2-(4-Fluorophenyl)-6-methoxybenzo[b]thiophene

Participants

Reaction Steps

To a 5 mL microwave vial was added a solution of 6-methoxybenzo[b]thiophene (400 mg, 2.44 mmol) in anhydrous DMA (3 mL) followed by 1-bromo-4-fluorobenzene (448 mg, 2.56 mmol), chloro[2-(dicyclohexylphosphino)-3,6-dimethoxy-2′,4′,6′-tri-1-propyl-1,1′-biphenyl][2-(2-aminoethyl)phenyl]palladium(II) (BrettPhos palladacycle 1st generation, 97 mg, 0.12 mmol), trimethylacetic acid (746 mg, 7.31 mmol) and potassium carbonate (1.01 g, 7.31 mmol). The microwave vial was sealed, purged with nitrogen and subjected to microwave irradiation at 150° C. for 2 h. Upon completion the reaction mixture was diluted with water and extracted with EtOAc. The combined organic layers were then washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo. The resulting crude material was purified via trituration 2× with heptane and the remaining triturate (containing some product) was concentrated and purified by column chromatography (SiO2, 0-30% EtOAc/Heptane) to afford 2-(4-fluorophenyl)-6-methoxybenzo[b]thiophene (340 mg, 1.32 mmol, 54% yield). 1H NMR (400 MHz, (CD3)2SO) δ ppm=3.79-3.93 (m, 3H), 7.01 (dd, J=8.59, 2.53 Hz, 1H), 7.24-7.42 (m, 2H), 7.56 (d, J=2.53 Hz, 1H), 7.67-7.86 (m, 4H). LC/MS (m/z, MH+): 258.8.

Provenance & Evidence