Trifluoroacetic acid → Ethyl 8-(1-acetyl-piperidin-4-yl)amino-1-methyl-4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

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Reaction Steps

To a suspension of 5.187 g (19 mmol) of ethyl 8-amino-1-methyl-4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate in dry dimethylformamide (120 mL), were added 1-acetyl-4-piperidone (4.7 mL, 38 mmol), CF3COOH (10 mL, 128 mmol) and NaBH(OAc)3 (8.862 g, 42 mmol). After 18 hours, NaOH 0.33N (800 mL, 264 mmol) was added dropwise to the mixture. The precipitate was filtered, washed with water and dried in oven to dryness to give 5.3 g (70% yield) of the title compound.

Provenance & Evidence