Hexachloroethane → 5-chloro-1-(2,4-difluoro-phenyl)-1H-[1,2,4]triazole

Participants

Reaction Steps

Under an atmosphere of nitrogen a solution of 1-(2,4-difluoro-phenyl)-1H-[1,2,4]triazole (15.7 g, 86.7 mmol) in THF (300 mL) at −78° C. was treated with n-butyllithium (38 mL, 2.5 M, 95.3 mmol) dropwise. After stirring for 1.5 h a solution of hexachloroethane (22.6 g, 95.3 mmol) in THF (30 mL) was added dropwise. The resultant reaction mixture was stirred for 1.5 h before allowing to warm to RT and quenching with water. The resultant mixture was diluted with water and extracted with ethyl acetate, the combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo to give an oil which crystallised on standing. The solid was recrystallised from cyclohexane to give 5-Chloro-1-(2,4-difluoro-phenyl)-1H-[1,2,4]triazole (12.4 g, 66%). 1H NMR δ (ppm) (CDCl3): 8.04 (1 H, s), 7.51-7.43 (1 H, m), 7.10-7.04 (2 H, m).

Provenance & Evidence