Propargyl alcohol → 9-Fluoro-2-(hydroxymethyl)pyrazolo[1,5-c]quinazolin-5(6H)-one

Participants

Reaction Steps

2.0 g (0.0113 mole) of 5-fluoro-3-diazooxindole (part B) and 13.1 g. (0.226 mole of 20 equivalents) of 97% propargyl alcohol are refluxed under argon for 4 hours. The reaction mixture is cooled, diluted with ether (200 ml) and stirred for 15 minutes. The beige-colored precipitates are filtered off and dried in vacuo overnight. Yield: 2.3 g, mp 295°-297°, 87.5% crude yield. The crude product is taken up in absolute ethanol (500 ml), treated with activated carbon, filtered through a Celite pad; the pad is washed with 50 ml of hot ethanol. The clear filtrate is concentrated down to a volume of 100 ml and cooled. The white precipitates are filtered off and dried in vacuo at 60° to yield the product (title compound) 1.16 g, mp 303°-304°.

Provenance & Evidence