Sodium Carbonate → 3-(2,4-bis(5-methylthiophen-2-yl)-1H-imidazol-1-yl)-9-methyl-9H-carbazole

Participants

Reaction Steps

A mixture of 3-(2-iodo-4-(5-methylthiophen-2-yl)-1H-imidazol-1-yl)-9-methyl-9H-carbazole 10 (920 g, 2.0 mmol), 5-methylthiophene-2-boronic acid pinacol ester (880 mg, 3.9 mmol), Na2CO3 (1.03 g, 9.81 mmol) in H2O (5 mL) and DMF (20 mL) was degassed (N2 bubbling). Pd(PPh3)4 (60 mg) was added and the mixture was heated to reflux for 8 h. The mixture was allowed to cool to room temperature and concentrated. The residue was washed with H2O (3 times) and EtOAc (1 time). The solid material was transferred to a soxlet apparatus and the material extracted with EtOAc. The organic extract was concentrated to ˜10 mL and the solid material was collected and recrystallised (EtOAc) to give 3-(2,4-bis(5-methylthiophen-2-yl)-1H-imidazol-1-yl)-9-methyl-9H-carbazole 11 (1.19 g, 76%) as colourless crystals. A portion of this material was further purified by sublimation (220° C., 10−6 mBar): m.p. 248-255° C. (DSC)1H NMR (CDCl3, 400 MHz) δ 2.33 (s, 3H), 2.51 (d, J=0.6 Hz, 3H), 3.94 (s, 3H), 6.48 (br s, 1H), 6.72 (d, J=2.5 Hz, 1H), 7.22 (s, 1H), 7.30 (t, 7.6 Hz, 1H), 7.43 (dd, J 2.0, 8.6 Hz, 1H), 7.49 (d, 8.5 Hz, 2H), 7.57 (dt, J 1.0, 7.6 Hz, 1H), 8.08 (d, 7.7 Hz, 1H), 8.10 (d, J=1.8 Hz, 1H); 13C NMR (CDCl3, 100 MHz) δ 15.1, 15.4, 109.0, 109.2, 117.9, 119.2, 119.8, 120.8, 122.2, 123.3, 124.5, 125.9, 126.1, 126.9, 141.1, 141.8, 142.6; HRMS (EI) m/z 439.1163 C24H22N2S [M]+. requires 439.1171.

Provenance & Evidence