Synthesis of 2H-pyrazolo[3,4-b]pyridin-3-oles via cyclization of pyrazolacrylonitriles

Cocco MT;CONGIU, CENZO;ONNIS, VALENTINA

1994-01-01

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Abstract

The reaction of 1-acyl-3-amino-5-pyrazolones 1 with ethyl ethoxymethylenecyanoacetate and ethoxymethylenemalononitrile 2 is described. Thermal cyclization in phenyl ether of the obtained pyrazolacrylonitriles 3 provides good yields of pyrazolopyridin-3-ol derivatives 4.