3-(3H-imidazo[4,5-b]pyridin-2-yl)benzenamine synthesis

Yield:116489-65-7 80%

Reaction Conditions:

with polyphosphoric acid at 180; for 4 h;

Steps:

5.2. General procedure A2: synthesis of the benzoxazole core

General procedure: To 34 mL of polyphosphoric acid (1.5 g/mmol of limiting reagent)was added 2-amino-3-hydroxypyridine (1.0 eq) and the relevant benzoic acid (1.1 eq). The mixture was heated to 180 °C and stirred for 4 h, cooled and poured into 5 M sodium hydroxide. The resulting precipitate was filtered and recrystallised from ethyl acetate to give the desired benzoxazole core.

References:

Ferrins, Lori;Rahmani, Rapha?l;Sykes, Melissa L.;Jones, Amy J.;Avery, Vicky M.;Teston, Eliott;Almohaywi, Basmah;Yin, JieXiang;Smith, Jason;Hyland, Chris;White, Karen L.;Ryan, Eileen;Campbell, Michael;Charman, Susan A.;Kaiser, Marcel;Baell, Jonathan B. [European Journal of Medicinal Chemistry,2013,vol. 66,p. 450 - 465]