1H-Benzimidazole-2-acetonitrile

LIGHT BEIGE FINE CRYSTALLINE POWDER

To the dry solid of o-phenylene diamine (1.08 g, 0.01 mol), ethyl caynoacetate (1.13 g, 0.01 mol) was added. The reactionmixture was heated in an oil bath at 120°C for 30 min thenwas left to cool. The solid product produced upon trituratingwith diethyl ether was collected by filtration and crystallizedfrom ethanol.A mixture of 1.45 g (0.013 mol) of 4-substitutedbenzene-1, 2-diamine (1a-b) and 1.65 g/1.55 ml (0.014 mol) of ethylcyanoacetate(2b) was heated under reflux for 10 h in 6.7 ml(0.061 mol). After cooling to room temperature, the precipitatewasfiltered and washed with anisole. The product was dried andrecrystallized with ethanol/water mixture to get compound (3a)(88percent yield). In the case of chloro-substituted benzene-1, 2-diamine(1b), a sticky product was obtained which was extracted with etherto get the pure compound (3b).4.2.1. 2-Cyanomethyl-1H-benzimidazole (3a, C9H7N3) brownYield 85percent, mp 210-212 °C; Rf 0.60 [toluene: ethyl acetate:formic acid (5:4:1)]; IR (KBr) (cm1): 3383 (NH str), 2253 (C^Nstr); 1H NMR (300 MHz, DMSO-d6) δ(ppm): 4.37 (s, 2H, eCH2CN), 7.18 (dd, J 3.0, 3.3 Hz, 2H, H-5, 6 benzimidazole), 7.55 (d, 2H, J 8.6 Hz, H-4, 7 benzimidazole), 12.63 (bs, 1H, eNH, D2Oexchangeable). 13C NMR (75 MHz, DMSO-d6) δ(ppm): 153.88, 138.04, 132.80, 126.54, 122.15, 47.00. Anal. Calcd.: C, 68.78; H, 4.49;N, 26.74; Found: C, 68.75; H, 4.45; N, 26.76.A mixture of o-phenylenediamine 10 (0.01mol, 1.08 g) and ethyl cyanoacetate (0.01 mol, 1.7 g) were refluxed in ethanol (30 mL) for 20 min. After cooling, the solution was extracted with ether (3 x 25 ml). The solvent was evaporated and the resultant solid product 11 was recrystallized from ethanol as a brown crystals; yield 75percent; mp 212 °C; A mixture of o-phenylene diamine (16.2 g, 0.15 mol) and ethyl cyanoacetate (25.4 g, 0.22 mol) and o-xylene (160 ml)was refluxed for 10–12 h in flask equipped with dean-stark trap. Then the reaction mixture was allowed to stand overnight at room temperature. The obtained solid was filtered and dried. The compound was recrystalised by 95percent ethyl alcohol.Yield =60 percent, m.p. 206 °C (lit. 207 °C)

Used in synthetic dyes, pigments, etc.

Molecular Weight:157.17
XLogP3:1.4
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:157.063997236
Monoisotopic Mass:157.063997236
Topological Polar Surface Area:52.5
Heavy Atom Count:12
Complexity:205
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes