Research on unsaturated azole derivatives

Synthesis and Antifungal Activity of 2-Chloromethyl-1H-benzimidazole Derivatives against Phytopathogenic Fungi in Vitro

“…Intermediates 1 and 6 were synthesized from o -phenylenediamine using the reported procedure. − Intermediate 2 was synthesized according to reported literature…”

“…A mixture of 4-nitro-2-amino-1- N -methylaniline (3.52 g, 21 mmol) and chloroacetic acid (2.58 g, 25.2 mmol) was refluxed for 4 h in 45 mL of 4 N HCl and then cooled to room temperature and adjusted to pH = 7 with ammonia. A gray residue was obtained. − Purification by column chromatography on neutral Al 2 O 3 eluting with CHCl 3 –MeOH (100:0.8) gave compound 6 as a yellow solid (3.37 g, yield 71%), mp, 180–182 °C (lit . 191–192 °C).…”

Synthesis, structural characterization of benzimidazole-functionalized Ni(II) and Hg(II) N-heterocyclic carbene complexes and their applications as efficient catalysts for Friedel–Crafts alkylations

“…Synthesis of 2-chloromethyl-1-ethylbenzimidazole (1) [29,59] A mixture of N-ethylbenzene-1,2-diamine (6.8 g, 50 mol) and chloroacetic acid (7.1 g, 75 mmol) was refluxed in 75 mL of 4 N HCl for overnight. The reaction mixture was neutralized with aqueous K 2 CO 3 and the precipitate product was collected by filtration and then purified by flash chromatography (ethyl acetate/petroleum ether ¼ 1/1) to give a white powder.…”

“…The ligand precursor [HL 1 ]PF 6 (2a) and [HL 2 ]PF 6 (2b), containing benzimidazole and pyridyl group, were prepared by refluxing 2-chloromethyl-1-ethyl-benzimidazole [29,59] with N-(6-methylpyridyl-methyl)imidazole and N-(6-methylpyridylmethyl) benzimidazole in toluene and subsequent anion exchange reaction with NH 4 PF 6 in water affording high yields, 87% for 2a and 79% for 2b (Scheme 1). The 1 H NMR spectrum of 2a and 2b in DMSO-d 6 showed a downfield resonance signal at 9.45 and 10.11 ppm, assignable to the acidic NCHN proton of the imidazolium ring.…”

Benzimidazole- and benzothiazole-quinones: excellent substrates for NAD(P)H:quinone oxidoreductase 1

“…The 1,2-diamine was dissolved in hydrochloric acid (4 M; 43 ml), and glycolic acid (8.34 g, 109.7 mmol) was added to the reaction mixture, which was stirred under reflux for 4 h. After cooling, the mixture was basified with sodium hydrogen carbonate to pH = 6.5. The mixture was extracted with dichloromethane and the combined organic layers dried over MgSO 4 , filtered and the filtrate evaporated under reduced pressure to yield the title compound (2.60 g, 49%) as a beige crystalline solid, recrystallized from ethyl acetate-pentane; mp 193-195 • C (lit., 47…”