1H-Benzimidazole-2-methanamine

General procedure: o-Phenylenediamine (0.54 g, 5 mmol) and required amino acid or anthranilic acid (7 mmol) was added sequentially to 10 ml of toluene in a quickfit flask. The reacting mixture was heated under reflux at carefully controlled temperature of 85 – 95 oC for 9 h under the influence of a magnetic stirrer to obtain coloured solution which was allowed to cool overnight. The crystals formed was filtered and air-dried to afford (1H-benzo[d]imidazol-2-yl)methanamine, 10a in 97.3percent yield. Due to high efficiency observed in Method B for the synthesis of 10a, it was therefore adopted as the viable method for the synthesis of the rest of the compounds 10b-i. Synthesis of (1H-benzo[d] imidazol- 2- yl) methanamine, 10aTreatment ofo-phenylenediamine (0.54 g, 5 mmol) with L-glycine (0.53 g, 7 mmol) afforded(1H-benzo[d]imidazol-2-yl)methanamine, 10a.1HNMR (400 MHz, DMSO-d6) δ: 7.95 (s, 1H, NH), 7.82-7.80 (d, J= 8.03 Hz, 2H, Ar-H), 7.17-7.13 (m, 2H, Ar-H), 6.44-6.42 (t, J= 5.78 Hz, 2H, NH2-CH2), 3.55-3.53 (t, J= 5.78 Hz, 2H, CH2-NH2). 13C-NMR (100 MHz, DMSO-d6) δ: 142.6, 139.3, 138.9, 125.3, 125.3, 119.2, 119.2, 41.7 ppm. lmax in nm (log εmax): 236 (1.7782), 290 (1.324), 407 (0.8541). IR (KBr): 3384, 3363 (N-H of NH2, two bands), 3245 (N-H), 3021 (C-H aromatic), 2930 (C-H aliphatic), 1605 (C=C), 1580 (C=N), 741 (Ar-H) cm-1. MS: in m/z (rel. percent): 295.04 (2M + 1, 10.5percent), 148.01 (MH, 24.5percent), 147.03 (M+, 20percent), 132.04 (M – NH, 100percent), 118.07 (M – CH2=NH, 35.3percent), 76.11 (68.3percent).A solution of 1, 2-phenylenediamine (13 g, 0.12 mol) and glycine (18 g, 0.24 mol) in 4 N hydrochloric acid (40 mL) was heated to reflux with stirring for 2 h. The progress of the reaction was monitored by TLC. On completion of the reaction, the reaction mixture was cooled to room temperature and the pH was adjusted to 7.2 using 1 N sodium hydroxide solution to obtain buff colored product 1. The product was recrystallized using rectified sprit as solvent.Yield: 87 percent, mp 261−263 °C, RGeneral procedure: General procedure for the synthesis of (1H-benzimidazole-2-yl)alkylamines was adapted from the Phillips procedure.

Molecular Weight:147.18
XLogP3:0.6
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:147.079647300
Monoisotopic Mass:147.079647300
Topological Polar Surface Area:54.7
Heavy Atom Count:11
Complexity:137
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes