Triethylamine → 2,4-difluoro-alpha-(1H-1,2,4-triazol-1-yl)acetophenone hydrochloride

Participants

Reaction Steps

To a mixture of 1,2,4-triazole (30.4 g, 0.44 mole) and triethylamine (15.1 g, 0.15 mole) in refluxing ethyl acetate (186 ml) was added a solution of 2-chloro-2',4'-difluoroacetophenone (38.1 g, 0.2 mole) in ethyl acetate (80 ml). The mixture was refluxed for six hours then cooled to room temperature and the insolubles were removed by filtration. The filtrate was washed with water (2×200 ml) and then the solvent was removed by distillation at reduced pressure. The crude product was dissolved in ethyl acetate (150 ml) then 25% w/v HCl gas in isopropanol was added. The mixture was granulated at 0° C. for one hour and then the solid was collected by filtration and dried to give the title compound (21.6 g, 40%), melting point 167°-170° C. IR (KBr) and NMR (DMSO) were consistent with the desired structure.

Provenance & Evidence