Synthesis
Example 17: Synthesis of N'-(3,4-dimethoxybenzylidene)-3-(4-methyl-1H-benzo[d]imidazol-1-yl)propanoylhydrazine.
[0523] (a) Preparation of 4-methyl-1H-benzo[d]imidazole: 3-methylbenzene-1,2-diamine (400 mg, 3.27 mmol), triethyl orthoformate (0.65 mL, 3.92 mmol) and iodine (83 mg, 0.327 mmol) were mixed in acetonitrile (10 mL) and stirred overnight at room temperature. After completion of the reaction, the reaction mixture was diluted with ethyl acetate and washed with saturated aqueous sodium bicarbonate. The organic layer was separated and dried with anhydrous sodium sulfate. Purification by silica gel column chromatography using ethyl acetate-hexane (0 to 80%) as eluent afforded the target product 4-methyl-1H-benzo[d]imidazole (310 mg, 72% yield).
References
[1] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2008, vol. 47, # 7, p. 1154 - 1159
[2] Monatshefte fur Chemie, 2007, vol. 138, # 1, p. 89 - 94
[3] Journal of Heterocyclic Chemistry, 2007, vol. 44, # 6, p. 1509 - 1512
[4] Patent: WO2010/132615, 2010, A1. Location in patent: Page/Page column 113
