Toluene → [3-(N'-benzhydrylidene-hydrazino)-thiophen-2-yl]-(1-benzyloxymethyl-1H-benzoimidazol-2-yl)-methanone

Participants

Reaction Conditions

Reaction Steps

A mixture of (1-benzyloxymethyl-1H-benzimidazol-2-yl)-(3-bromothiophen-2-yl)methanone (500 mg, 1.06 mmol, Example 1C), benzophenone hydrazone (276 mg, 1.41 mmol), palladium(II) acetate (13.4 mg, 0.06 mmol), 1,1′-Bis(diphenylphosphino)-ferrocene (57.5 mg, 0.104 mmol), cesium carbonate (570 mg, 1.75 mmol), and toluene (10 mL) under nitrogen is stirred at 90° C. for 15 hours. The dark reaction is cooled to ambient temperature, diluted with ethyl acetate, filtered, and the insolubles washed with ethyl acetate. The combined filtrate and washings were washed with water and brine successively, dried over magnesium sulfate, and then concentrated under reduced pressure to afford a yellow oil. The crude material is chromatographed on silica, eluting with 80% dichloromethane/heptane, to give [3-(N′-benzhydrylidene-hydrazino)-thiophen-2-yl]-(1-benzyloxymethyl-1H-benzoimidazol-2-yl)-methanone as a yellow-orange powder: TLC Rf 0.30 (silica, 80% dichloromethane/heptane); LC/MS: (M+H 543.1, RT=4.68 minutes); 1H NMR [(CD3)2SO), 300 MHz]: δ 11.64 (s, 1H), 8.08 (d, 1H, 5.5 Hz), 7.84-7.13 (m, 20H), 6.00 (s, 2H), 4.46 (s, 2H).

Provenance & Evidence