Potassium Phosphate, Tribasic → HCID 86699581, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of [2-chloro-4-(trifluoromethyl)phenyl]boronic acid (4.5 g, 20.06 mmol) in water (30 mL) and dioxane (200 mL) was added K3PO4 (5.7 g, 26.85 mmol), 5-chloro-4-iodo-2-nitroaniline (4 g, 13.40 mmol) and Pd(PPh3)4 (800 mg, 0.69 mmol) maintained with an inert atmosphere of nitrogen and stirred overnight at 95° C. The resulting mixture was concentrated under vacuum to give a residue, which was purified by a silica gel column with 10% ethyl acetate in petroleum ether to produce 5-chloro-4-[2-chloro-4-(trifluoromethyl)phenyl]-2-nitroaniline as a yellow solid (3 g, 32%). Next, to a solution of 5-chloro-4-[2-chloro-4-(trifluoromethyl)phenyl]-2-nitroaniline (3 g, 8.54 mmol) in ethanol (80 mL) was added hydrochloric acid (2 mL) and Zn powder (3.4 g, 52.3 mmol) in portions. The resulting solution was stirred for 2 h at reflux. The resulting mixture was concentrated under vacuum and dissolved in water (100 ml) adjusted to pH 8 with sodium carbonate and extracted with ethyl acetate (3×100 mL). The combined organic layers were dried over anhydrous sodium sulfate and concentrated under vacuum to give the residue, which was purified by a silica gel column with 20% ethyl acetate in petroleum ether to produce 4-chloro-5-[2-chloro-4-(trifluoromethyl)phenyl]benzene-1,2-diamine as brown oil (1 g, 36%). Finally, the solution of 4-chloro-5-[2-chloro-4-(trifluoromethyl)phenyl]benzene-1,2-diamine (100 mg, 0.31 mmol) in TFA (5 mL) and hydrochloric acid (conc, 1 mL) was stirred overnight at 80° C. and quenched with water (100 ml), adjusted pH to 8 with saturated aqueous sodium carbonate and extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over anhydrous sodium sulfate and concentrated under vacuum to give a residue, which was purified by a silica gel column with 10% ethyl acetate in petroleum ether to produce 5-chloro-6-[2-chloro-4-(trifluoromethyl)phenyl]-2-(trifluoromethyl)-1H-1,3-benzodiazole as a white solid (107.8 mg, 87%).

Provenance & Evidence