Triethylamine → 6-Methoxy-2-(4-methoxyphenyl)-1-benzothiophene-3-carbonitrile

Participants

Reaction Steps

To a slurry of 6-methoxy-2-(4-methoxyphenyl)benzo[b]thiophene-3-carboxamide (0.4488 g, 1.43 mmol) in tetrahydrofuran (20 ml) at 5° C. is added triethylamine (0.5 ml, 3.58 mmol) and trifluoroacetic acid anhydride (0.26 ml, 1.79 mmol). The cooling bath is removed and the reaction allowed to warm to room temperature and stir for 16 hours. The contents are partitioned between water and methylene chloride, and the organic layer is separated, dried over magnesium sulfate, filtered and concentrated to a solid, which is chromatographed on silica gel (9:1 dichloromethane:toluene) to afford 386.9 mg (92%) of title compound as a solid: mp 141.7-142.9° C. IR (KBr) 2985, 2214, 1610, 1498, 1479, 1260, 1033 cm-1 ; 1H NMR (CDCl3): δ7.82 (d, 2 H, J=8.9 Hz), 7.81 (d, 1 H, J=8.8 Hz), 7.28 (d, 1 H, J=2.2 Hz), 7.12 (dd, 1 H, J=8.9, 2.2 Hz), 7.02 (d, 2 H, J=8.9 Hz), 3.90 (s, 3 H), 3.88 (s, 3 H); 13C NMR (CDCl3): d 161.1, 158.5, 155.5, 131.0, 138.5, 133.1, 129.4, 124.3, 123.0, 115.8, 114.7, 104.9, 100.2, 55.8, 55.5. Anal. Calcd. for C17H13NO2S: C, 69.13; H, 4.44; N, 4.74; S, 10.85. Found: C, 68.86; H, 4.66; N, 4.52; S, 10.76.

Provenance & Evidence