1,1'-Carbonyldiimidazole → HCID 178423908, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4,9-dihydro-5-methyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxylic acid (4.86 g; 0.02 mole) in dimethylformamide (50 ml) is added 1,1'-carbonyldiimidazole (4.86 g; 0.03 mole). The reaction mixture is heated at 100° C. for 12 min, then cooled and diluted with ether (75 ml) and methylene chloride (25 ml). The tan solid is filtered off and suspended in cold (0° C.) DMF (50 ml). Annydrous ammonia is bubbled through for 10 min and the resulting solution is allowed to stand at room temperature overnight. The dimethylformamide solution is evapoated to dryness under reduced pressure and the residue is washed with methylene chloride and ether and dried. Yield 3.0 g; mp 340°-345° C. (d). By the same procedure, starting with the corresponding 8-trifluoromethyl compound, the product obtained is 4,9-dihydro-8-trifluoromethyl-9-oxo-pyrazolo[5,1-b]quinazoline-2-carboxamide.

Provenance & Evidence