Dimethylformamide → 8-tert-Butyl-6,7-dihydropyrrolo(3,2-e)-5-methylpyrazolo(1,5-a)pyrimidine-3-carbonitrile

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Reaction Steps

A mixture of 88.9 g of Compound (VI) [R2 =H, R3 =CN], 33.0 g of tert-butylamine, 89 g of anhydrous potassium carbonate, and 700 ml of anhydrous dimethylformamide were stirred at room temperature overnight. To the reaction solution was added 500 ml of chloroform to remove insoluble substances by filtration. The filtrate was condensed under reduced pressure to dryness. The residue was dissolved in chloroform, washed with water, and dried over anhydrous sodium sulfate. The residue from which the solvent was evaporated was recrystallized in benzene to produce 73.6 g of 8-tert-butyl-3-cyano-6,7-dihydro-5-methyl-8H-pyrrolo [3,2-e]pyrazolo[1,5-a]pyrimidine [R1 =C(CH3)3, R2 =H, R3 =CN in formula (I)] having a melting point of 220°-224° C. at a yield of 82.8%.

Provenance & Evidence