3- Alkynylpyrazole-4 3 -diazonium salts

In general, it is diffieult to prediet the outeome of eyelizations of alkynylpyrazole diazonium salts, even with elosely related arrangements of funetional groups, sinee reaetion ean oeeur at both the a- and /3-earbon atoms of the aeetylenie substituent. Moreover, it is known that the eleetrophilieity of the diazo group and the nueleophilieity of a triple bond markedly depend on their positions in the pyrazole ring and that this ean affeet both the eourse and ease of eyelization and even its viability (83IZV688). 

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