Sodium Hydroxide → 7-methyl-4-oxo-1-(tetrahydro-2H-pyran-4-yl)-4,5-dihydro-1H-pyrazolo[4,3-c]quinoline-8-carboxylic acid

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Reaction Conditions

Reaction Steps

To a mixture of 2.63 g of methyl 7-methyl-4-oxo-1-(tetrahydro-2H-pyran-4-yl)-4,5-dihydro-1H-pyrazolo[4,3-c]quinoline-8-carboxylate and 52 mL of methanol was added 10.2 mL of a 3 M aqueous sodium hydroxide solution, followed by stirring at 60° C. for 20 hours. The insoluble material was filtered, and the filtrate was adjusted to pH 2 with concentrated hydrochloric acid, and stirred for 1 hour. The precipitated powder was collected by filtration and dried under reduced pressure to obtain 2.49 g of 7-methyl-4-oxo-1-(tetrahydro-2H-pyran-4-yl)-4,5-dihydro-1H-pyrazolo[4,3-c]quinoline-8-carboxylic acid as powder.

Provenance & Evidence