1,1'-Carbonyldiimidazole → 8-(3-(Trifluoromethyl)phenyl)-3H,6H-1,4,5a,8a-tetraazaacenaphthylene-3,5(4H)-dione

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Reaction Steps

To a stirred mixture of 10.0 g of 4,5-dihydro-7-(3-(trifluoromethyl)phenyl)pyrazolo(1,5-a)pyrimidine-3-carboxamide (prepared as described in Example 8) in 200 ml of dioxane at room temperature under nitrogen is added 20.0 g of 1,1'-carbonyldiimidazole. The mixture is then heated at reflux for 5 hours, and then is cooled and filtered. The filtrate is evaporated to dryness in vacuo and an excess of water is added to the residue. The white solid which forms is collected and is recrystallized from acetonitrile-ethanol to give 6.5 g of the desired product as a white solid, mp 260-262° C.

Provenance & Evidence