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a) A mixture of 4-chloro-1,2-benzenediamine (105 g, 736 mmol, 1 eq.) and ethanoic acid (112 g, 2 eq.) in xylene (1500 mL) was stirred and refluxed at 150 °C for 4 h. The reaction was carried out with the addition of 3N hydrochloric acid (480 mL). Upon completion of the reaction, the reaction solution was cooled to 60 °C and acidified by slow addition of 3N hydrochloric acid (480 mL), followed by adjusting the pH with ammonia to 7-8. The reaction mixture was filtered and the solid product was collected and washed with water and tert-butyl methyl ether sequentially to afford 123 g of (6-chloro-1H-benzimidazol-2-yl)methanol in 82% yield.

[1] Molecules, 2015, vol. 20, # 8, p. 15206 - 15223
[2] Patent: WO2014/60411, 2014, A1. Location in patent: Page/Page column 58
[3] Patent: WO2015/158653, 2015, A1. Location in patent: Page/Page column 37; 38
[4] Annales Pharmaceutiques Francaises, 2003, vol. 61, # 1, p. 57 - 61
[5] Bulletin of the Korean Chemical Society, 2013, vol. 34, # 4, p. 1272 - 1274