Carbon Tetrachloride → 8-(4-Chlorophenyl)-3-[3-methoxy-4-(2-methyl-1,3-oxazol-5-yl)phenyl]-8-methyl-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine

Participants

Reaction Conditions

Reaction Steps

To a mixture of N′-[5-chloro-2-(4-chlorophenyl)-2-methylpentanoyl]-3-methoxy-4-(2-methyl-1,3-oxazol-5-yl)benzohydrazide (4.0 g) and carbon tetrachloride (1.57 mL) in acetonitrile (25 mL) was added triphenylphosphine (8.56 g), and the mixture was stirred at 80° C. for 1 hr. The reaction mixture was diluted with ethyl acetate and saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane). Another lot synthesized similarly was combined and the mixture was dissolved in diethyl ether. The insoluble material was removed by filtration. The solvent in the filtrate was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane). To a mixture of the purified product in DMSO (50 mL) was added sodium azide (1.88 g), and the mixture was stirred at 70° C. for 18 hr. The reaction mixture was diluted with ethyl acetate, water and saturated brine, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. To a mixture of the residue in THF (50 mL)/water (5 mL) was added triphenylphosphine (7.60 g), and the mixture was stirred at 60° C. for 2.5 hr. The solvent in the reaction mixture was evaporated under reduced pressure. Acetic acid (25 mL) was added to the residue, and the mixture was stirred under heating with reflux for 1 hr. The reaction mixture was diluted with ethyl acetate and saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (methanol/ethyl acetate) to give the title compound (3.80 g).

Provenance & Evidence