Carbon Dioxide → HCID 67203453, compound

Participants

Reaction Conditions

Reaction Steps

A 12 L reaction vessel was charged with 2-propyl-2,5-dihydro-4H-pyrazolo[3,4-c]quinolin-4-one (103.40 g, 455 mmol), tetrahydrofuran (THF, 6.1 L), and N,N,N′,N′-tetramethylethylenediamine (392 mL, 2.59 mol), and the resulting suspension was cooled in an ice bath. n-Butyllithium (510 mL of a 2.5 M solution in hexane, 1.27 mol) was added over 65 minutes, and the reaction was allowed to stir at 5° C. for 20 minutes. The contents of the 12 L vessel were transferred via cannula over a period of 20 minutes to a 22 L vessel containing dry ice (3 kg) and diethyl ether (2 L). The reaction was stirred overnight, water (3 L) was added, the organic layer was drawn off, and the aqueous layer was washed with chloroform (4×500 mL). The aqueous layer was acidified by treatment with 2 M HCl (1.6 L), and the resulting suspension was stirred overnight. The solid was collected by filtration and dried on suction for 2 days to afford 69.47 g of 4-oxo-2-propyl-4,5-dihydro-2H-pyrazolo[3,4-c]quinoline-1-carboxylic acid as an off-white solid.

Provenance & Evidence