Ethyl Acetate → 4-(Trifluoromethyl)benzyl-8-chloro-7-(4-chlorophenyl)-2H-[1,2,4]triazolo[4,3-b]pyridazin-3-one

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Reaction Conditions

Reaction Steps

To a stirring suspension of 8-chloro-7-(4-chlorophenyl)-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (1.12 g, 4.0 mmol) and 4-(trifluoromethyl)benzyl bromide (1.24 g, 5.2 mmol) in DMF (15 mL) at RT under argon was added K2CO3 (0.83 g, 5.2 mmol). The resulting mixture was heated at 55° C. for 2 h. After 2 h, HPLC/MS analysis indicated the reaction was complete. The reaction mixture was cooled to RT and EtOAc (100 mL) was added. The resulting mixture was washed with saturated NaCl (50 mL×2). The organic layer was dried (Na2SO4), filtered and concentrated under vacuum with co-evaporation of toluene (10 mL×2) to obtain a dark yellow solid. This crude product was washed with MeOH (10 mL×2), then dried under vacuum at room temperature for 3 h to obtain the title compound, 2-(4-(trifluoromethyl)benzyl)-8-chloro-7-(4-chlorophenyl)-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (1.3 g, 74%) as a yellow solid. MS [M+H]+ 439; HPLC retention time=3.92 min; 1HNMR (400 MHz, CDCl3) δ 9.00 (s, 1H), 7.45-7.61 (m, 8H), 5.32 (s, 2H).

Provenance & Evidence