Hantzsch Multicomponent Synthesis of Heterocycles

In 1881, Hantzsch first noted the formation of 1,4-dihydro-pyridines 547 through the reaction of ethyl acetoacetate 

Both 1,4-dihydropyridines and pyrroles are widely spread motives in natnral prodncts and drngs (Figs. 13.1 and 13.2). Several calcinm channel blockers 550-557 with their additional nse in the treatment of, for example. 

Among the pyrrole-containing natnral products and therapeutics, PNU-156804 559 expresses promising activity in the suppression of heart allograft rejection [216], and BE18591 561 do so against tnmors [217] (Fig. 13.2). 

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