Benzaldehyde → HCID 69135079, compound

Participants

Reaction Conditions

Reaction Steps

6.4 g (26.7 mmol) 6-bromo-1,2-dimethyl-1H-benzimidazol-4-ylamine, 8.5 g (80 mmol) benzaldehyde and 0.3 g p-toluenesulphonic acid monohydrate in 80 ml toluene were refluxed on a Dean-Stark-trap. After complete reaction, the mixture was evaporated to one third of its volume and diluted with 50 ml tetrahydrofuran. The mixture was cooled to 0° C. and 80 ml (80 mmol) vinylmagnesiumbromide (1M solution in tetrahydrofuran) were added during 45 min. After 30 min., the reaction mixture was hydrolyzed with saturated ammonium chloride solution, diluted with water and extracted with ethyl acetate. The organic phase was separated, washed with water, dried over anhydrous magnesium sulphate and evaporated. The residue was purified by column chromatography on silica gel (petroleum ether/ethyl acetate=7:3). Crystallization from diisopropyl ether afforded 4.2 g (44%) of the title compound as a colourless solid. m.p. 137-139° C.

Provenance & Evidence