Dimethylformamide → 3-[1-[4-[2-(3-oxo-2,3-dihydro-4H-1,4-benzothiazin-4-yl)ethoxy]benzyl]-3-phenyl-1H-pyrazol-4-yl]propionic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 3-[1-[4-(2-bromoethoxy)benzyl]-3-phenyl-1H-pyrazol-4-yl]propionate (883 mg), 2H-1,4-benzothiazin-3(4H)-one (320 mg), potassium carbonate (530 mg) and N,N-dimethylformamide (10 ml) was stirred at 80° C. for 8 hours. The reaction mixture was poured into water, and extracted with ethyl acetate. The ethyl acetate layer was washed successively with dilute hydrochloric acid and saturated aqueous sodium chloride solution, dried (MgSO4) and concentrated. The residue was subjected to silica gel column chromatography to obtain a colorless oily substance from the fraction eluted with ethyl acetate-hexane (1:2, volume ratio). After a mixture of the resulting colorless oily substance, 1N aqueous sodium hydroxide solution (5 ml), tetrahydrofuran (5 ml) and ethanol (5 ml) was stirred at room temperature for 3 hours, 1N hydrochloric acid (5 ml) was added to the mixture, and then the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with a saturated aqueous sodium chloride solution, dried (MgSO4), and concentrated to obtain 3-[1-[4-[2-(3-oxo-2,3-dihydro-4H-1,4-benzothiazin-4-yl)ethoxy]benzyl]-3-phenyl-1H-pyrazol-4-yl]propionic acid (680 mg, yield: 69%) as a colorless amorphous substance.

Provenance & Evidence