N-(2-BROMO-PHENYL)-GUANIDINE synthesis

Yield:-

Reaction Conditions:

Stage #1: thioureawith copper(ll) sulfate pentahydrate;sodium acetate in dimethyl sulfoxide;N,N-dimethyl-formamide at 20; for 1 h;
Stage #2: 2-bromoanilinewith copper(ll) sulfate pentahydrate in dimethyl sulfoxide at 20;Reagent/catalyst;

Steps:

3.2. General Procedure for the Synthesis of 2-(N-arylamino)Benzimidazole

General procedure: To a stirred solution of DMSO (2-3 mL), thiourea (1 mmol, 76 mg) was added slowly, followedby the addition of NaOAc (1 mmol, 82 mg) and a copper source (50 mol%) at room temperature.The whole reaction mixture was stirred for 1 h (until a black-colored solution was obtained) at roomtemperature. To this, 2-bromoaniline (2 mmol, 344 mg) was added. After completion of the reaction(monitored by TLC), the reaction mixture was transferred into tubes and the mixture was centrifugedfor 10 min. A black solid was then recovered from the tubes, and to this a clear solution of iodobenzene(1 mmol, 204 mg), K2CO3 (2 mmol, 277 mg), Cu(SO)4.5H2O (20 mol%, 50 mg), and 1,10-phenanthroline(20 mol%, 36 mg) was added slowly in several minutes, and the reaction mixture was then allowedto stir for 18 h at 120 °C. Progress of the reaction was monitored by TLC, using ethyl acetate andhexane (1:4). After completion of the reaction, the reaction mixture was cooled to room temperature.Then, the solution was washed with ethyl acetate (7 mL) and water (3 mL) for 5 times. The organic layerwas evaporated, and the crude reaction mixture was purified on asilica gel (60-120 mesh) column bychromatography to obtain the final product 2-(N-arylamino)benzimidazole, which was characterizedby NMR (1H and 13C), IR, and mass spectral data.N-Phenyl-1H-benzo[d]imidazol-2-amine (1a): White solid; yield 96%; mp 97-99 °C; 1H NMR (400 MHz,CDCl3) δ 7.78 (d,J = 6.8 Hz, 2H), 7.26-7.11 (m, 7H), 6.12 (br s, 1H); 13C NMR (100 MHz, CDCl3) δ 139.2,137.2, 134.2, 132.6, 130.5, 129.9, 129.7, 127.3, 115.0, 114.7, 110.8; FT-IR (KBr) 3294, 3098, 1676, 1618, 1597,1542, 1478, 1413, 1253, 1076 cm-1. m/z (ESI-MS) 210.10 [M + H]+.

References:

Adil, Syed Farooq;Alduhaish, Osamah;Assal, Mohamed E.;Bollikolla, Hari Babu;Gollapudi, Ravi Kumar;Murthy Boddapati, S. N.;Nurbasha, Sharmila;Siddiqui, Mohammed Rafiq H.;Tamminana, Ramana [Molecules,2020,vol. 25,# 8]