Electric Literature of 615-16-7, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 615-16-7 name is 2-Hydroxybenzimidazole, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
General procedure: 4-Bromo-2-(substituted) benzonitrile 5a or 5b (5 mmol) was added to a mixture of 1H-benzo[d]imidazol-2(3H)-one (6) (10 mmol) and Cs2CO3 (10 mmol) in DMF (25.0 ml). After 12 h, 50 ml of ice water was added dropwise. The resulting suspension was filtered, and the filter cake was dried in a vacuum oven. The solid was purified by flash chromatography (50 % ethyl acetate in hexane) to afford 4-(2-oxo-2,3-dihydro-1H-benzo[d]imidazol-1-yl)-2-(substituted) benzonitrile (7a or 7b). 2-(Trifluoromethyl)-4-(1,2-dihydro-2-oxobenzo[d]imidazol-3-yl) benzonitrile (7a) Yield 62 %; White Solid; mp 232-233 C; IR (KBr) nu max: 3189, 3149 (N-Hstretch), 3072 (C-Harom), 2957, 2895, 2820 (C-Halk), 2230 (C:N), 1720 (C=O), 1611 (N-Hbend), 1575, 1507, 1481, 1439 (C=Carom), 1385, 1319, 1240, 1185, 1127, 1053 (C-Hbend), 1272, 558 (C-CF3) cm-1; 1H NMR (400 MHz, CDCl3, ppm): delta 9.372 (s, 1H, NH), 8.14 (s, 1H, H-2), 8.03 (d, 2H, H-5,H-6), 7.2 (m, 4H, phenyl); 13C NMR (100 MHz, CDCl3, ppm): delta 152.9 (C=O), 139.2 (C4), 135.6 (C6), 133.8, 133.1 (q, J = 65 Hz, C2), 128.5 (C0 1), 127.6 (d, J = 34 Hz, C5), 123.3 (C0 6), 122.8 (C0 3), 122.5 (q, CF3), 121.6 (C), 120.4 (C0 5), 114.8 (CN), 110.0 (C0 2), 108.7 (C0 4), 106.6 (C1); HRMS (ESI): m/z calculated for C15H8F3N3O [M?H]?: 304.06922; Found: 304.069.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Hydroxybenzimidazole, and friends who are interested can also refer to it.
Reference:
Article; Elancheran; Saravanan; Choudhury, Bhaswati; Divakar; Kabilan; Ramanathan; Das, Babulal; Devi; Kotoky, Jibon; Medicinal Chemistry Research; vol. 25; 4; (2016); p. 539 – 552;,
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem