摘要:
In the treatment of pyrazolo[1,5-a]pyridines with dimethylformamide and,phosphorus oxychloride, Vilsmeier-Haack formylation proceeded at the 3-position, giving 3-pyrazolo[1,5-a]pyridinecarboxaldehydes. Reaction of the pyrazolo[1,5-a]pyridine with acyl halide gave 3-acylpyrazolo[1,5-a]pyridines. Conversion of the formyl group into the alkenyl group was achieved easily by Wittig reaction.