2-Methoxyphenylhydrazine Hydrochloride → HCID 73291871, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(4-chlorophenyl)ethanone (2.0 g, 12.9 mmol) in anhydrous THF was cooled in a dry ice acetone bath and treated with sodium hexamethyldisilazid (14.2 mL, 1M in THF, 14.2 mmol). The resulting solution was stirred for 1 h at −78° C. and a solution of tetrahydro-pyran-4-carbonyl chloride (1.92 g, 12.9 mmol) in THF was slowly added. The resulting solution was stirred for 30 min at −78° C., allowed to warm up to room temperature and stirred for 5 h. The reaction was quenched by adding 6N HCl and extracted with EtOAc (×3). The organic fractions were combined and washed with sat. NaCl, dried over Na2SO4 and evaporated under vacuum. The resulting residue was purified by silica column chromatography to give 2 g (58%) of 1-(4-chlorophenyl)-3-(tetrahydro-2H-pyran-4-yl)propane-1,3-dione. 1-(4-chlorophenyl)-3-(tetrahydro-2H-pyran-4-yl)propane-1,3-dione 1 g (3.75 mmol) was taken in absolute ethanol (20 mL) and TEA (1.4 mL, 10 mmol) was added slowly. This solution was stirred for 20 min and added drop-wise to a solution of (2-methoxyphenyl)hydrazine hydrochloride (0.7 g, 4.0 mmol) in ethanol (20 mL). This solution was heated to 60° C. and stirred for 5 h. Ethanol was removed under vacuum and the residue was taken in EtOAc and washed with water, and sat. NaCl. The solution was dried over Na2SO4 and evaporated. The residue was purified by silica column chromatography to give 5-(4-chlorophenyl)-1-(2-methoxyphenyl)-3-(tetrahydro-2H-pyran-4-yl)-1H-pyrazole.

Provenance & Evidence