4-(1-tert-butyl-4-oxo-4,5-dihydro-1H-pyrazolo[4,3-c]pyridin-3-yl)thiophene-2-carboxamide → 4-(4-oxo-4,5-dihydro-1H-pyrazolo[4,3-c]pyridin-3-yl)thiophene-2-carboxamide

Participants

Reaction Steps

4-(1-tert-Butyl-4-oxo-4,5-dihydro-1H-pyrazolo[4,3-c]pyridin-3-yl)thiophene-2-carboxamide (475 mg) obtained in Example 129 was dissolved in a mixed solvent of trifluoroacetic acid (60 mL)/water (6 mL), and the mixture was heated with reflux at 24 hr. The reaction mixture was allowed to be cooled to room temperature, and concentrated under reduced pressure. The residue was extracted with ethyl acetate and saturated aqueous sodium hydrogencarbonate solution, and the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The obtained residue was crystallized from DMF-ethyl acetate, and dried in vacuum to give the title compound (240 mg).

Provenance & Evidence