Triethylamine → HCID 86654639, compound

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Reaction Steps

A 6-ethynyl-pyrazolo[1,5-a]pyridine of formula ID can be obtained by decarboxylation of an appropriately substituted 6-methoxy-pyrazolo[1,5-a]pyridine-3-carboxylic acid ester 22 with hydrobromic acid, yielding the corresponding pyrazolo[1,5-a]pyridin-6-ol derivative 23, which is converted to the triflate derivative 25 using trifluoromethanesulfonic anhydride 24 and a base such as triethylamine in a solvent such as dichloromethane. Sonogashira coupling of 25 with an aryl-acetylene of formula 3 yields the desired 6-ethynyl-pyrazolo[1,5-a]pyridine of formula ID (scheme 5).

Provenance & Evidence