Water → HCID 86699563, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-chloro-4-iodo-2-nitroaniline (5.0 g, 16.75 mmol) in dioxane (200 ml) was added water (20 ml), Pd(PPh3)4 (924 mg, 0.80 mmol), K3PO4 (7.0 g, 32.98 mmol) and [4-(trifluoromethyl)phenyl]boronic acid (6.3 g, 33.17 mmol) with stirring overnight at 100° C. under nitrogen. The resulting mixture was concentrated under vacuum and dissolved in water (250 ml), extracted with ethyl acetate (3×200 ml) and the organic layers combined, dried over anhydrous sodium sulfate and concentrated under vacuum to give the residue, which was re-crystallized from 50% ether in hexane to afford 5-chloro-2-nitro-4-[4-(trifluoromethyl)phenyl]aniline as a yellow solid (4.2 g, crude). Next, to a solution of 5-chloro-2-nitro-4-[4-(trifluoromethyl)phenyl]aniline (3.7 g, crude) in ethanol (300 ml) and hydrogen chloride (3.0 ml) was added Zn powder (4.55 g, 70.0 mmol) in several bacthes with stirring for 20 min at room temperature. The resulting solution was stirred for 7 h at 85° C. The solids were filtered out and the filtrate was concentrated under vacuum to give a residue, which was dissolved in water (100 ml). The mixture was adjusted to pH 7 with saturated aqueous sodium carbonate, extracted with ethyl acetate (3×300 ml) and the organic layers combined and dried over anhydrous sodium sulfate and concentrated under vacuum to give a residue that was purified by a silica gel column eluted with 10% to 50% ethyl acetate in petroleum ether to produce 4-chloro-5-[4-(trifluoromethyl)phenyl]benzene-1,2-diamine as brown oil (2.9 g,). Finally, the solution of 4-chloro-5-[4-(trifluoromethyl)phenyl]benzene-1,2-diamine (150 mg, 0.52 mmol) in pentafluoropropanoic acid (1 ml) was stirred overnight at 80° C. The result mixture was diluted with water (50 ml) and adjusted to pH 7 with saturated aqueous sodium carbonate. The resulting solution was extracted with ethyl acetate (3×50 ml), combined, dried over anhydrous sodium sulfate and concentrated under vacuum to give a residue, which was purified by a silica gel column eluted with 0.5% to 6.5% ethyl acetate in petroleum ether to produce 5-chloro-2-(pentafluoroethyl)-6-[4-(trifluoromethyl)phenyl]-1H-1,3-benzodiazole as a white solid (112.6 mg, 52%).

Provenance & Evidence