3-Oxo-3-phenylpropyne → 2-Benzoylpyrazolo[1,5-c]quinazolin-5(6H)-one

Participants

Reaction Steps

6.23 g (0.039 mole) of diazooxindole and 6.6 g (0.051 mole or 1.3 equiv) of the phenylethynyl ketone prepared as in part A above (dried on a porous plate before being weighed out) are suspended in benzene (275 ml) and the mixture is refluxed under N2 for 19 hours. The reaction mixture is cooled and the precipitates that form are filtered off, washed well with anhydrous ether (150 ml) and dried in a vacuum oven at ~70° for 1-1/2 hours. Yield: 10.3 g, m.p. 308°-311°. Additional product of 400 mg is obtained on refluxing the filtrate for another 24 hours. Total crude yield: 94.4%.

Provenance & Evidence