O-Phenylenediamine → 1H-Benzimidazole, 2-(diphenylmethyl)- (9CI)

Participants

Reaction Conditions

Reaction Steps

A mixture of diphenylacetaldehyde (2-1, 1.64 mL, 9.25 mmol, 1 equiv), 1,2-diaminobenzene (0.787 mL, 9.25 mmol, 1.00 equiv) and sodium metabisulfite (2.11 g, 11.1 mmol, 1.20 equiv) in DMF (10 mL) was heated at 100° C. for 18 h. The reaction mixture was cooled to 23° C. and filtered. The filtrate was suspended with sonication in a 1:1 mixture of saturated aqueous sodium chloride solution and saturated aqueous sodium carbonate solution then extracted with ethyl acetate (6×150 mL). The combined organic layers were dried voer sodium sulfate and concentrated. The residue was suspended in ethyl ether (50 mL), filtered, washed with ethyl ether (2×50 mL) and air dried to give 2-(diphenylmethyl)-1H-benzimidazole (2-2) as a white solid. 1H NMR (300 MHz, DMSO) δ 12.3 (br s, 1H), 7.50 (m, 2H), 7.34 (m, 8H), 7.24 (m, 2H), 7.08 (m, 2H), 5.74 (s, 1H). LRMS m/z (M+H) 235.0 found, 335.1 required.

Provenance & Evidence