Gas-Phase Synthesis of Pyrazolo[3,4-b]pyridin-4-ones

Abstract

Flash vacuum pyrolysis (FVP) at 500–600 °C of 1-substituted pyrazolylaminomethylene derivatives of Meldrum’s acid provides 1-substituted pyrazolo[3,4-b]pyridin-4-ones in high yields. If the 1-substituent is a tert-butyl group, FVP at 750–850 °C causes elimination of 2-methyl-1-propene to give the parent pyrazolo[3,4-b]pyridin-4-one.

Key words

gas-phase reactions - pericyclic reactions - heterocycles - Meldrum’s acid - medicinal chemistry

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