Substituent Transformations

A fairly large number of l,2,4-triazolo[l,5-c]pyrimidine derivatives were prepared via transformation of substituents attached to the skeleton of the parent system. The reported examples of such substituent transformation may collectively be categorized into the following types. 

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Owing to the number of different reactions in which they can be used, pyrazole aldehydes and ketones are the most interesting group of C-linked substituents. Transformations of the CHO group into CO2H, CH(OR)2, CH=CHR, etc., and of the COR group into... 

Table 7 Other substituent transformations a listing of the starting compound, functional group transformation, and references...

In Table 7, a great variety of other substituent transformations are summarized that have been published during the recent years. 

Electroreduction of pyridine derivatives bearing carboxylic acid derivatives (117 Scheme 23) leads to a variety of products from substituent transformation through ring reduction to ring cleavage. ... 

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