الخلاصة:
In the first chapter, we developed a novel catalytic synthesis of 3,4-
dihydropyrimidinones via Biginelli reaction in the presence of a bronsted ionic liquid [H-val]
HSO4 as the reaction medium. Then, we performed the synthesis of thiazolo[3,2-
a]pyrimidin-3(5H)-ones via Hantzsch thiazoles synthesis using bromide ethylacetoacetate as
an alkylatig agent in refluxed acetone, this novel method allowed to prepare these fused
heterocyclic compounds in good yields. Lability of hydrogens in previous derivatives allowed
to prepare new 2-benzilidénethiazolo[3,2-a]pyrimidin-3(5H)-ones via two methods: divergent
and convergent from DHPMs as starting materials.
In addition in the second chapter, we were interested in the development of novel
synthesis of 2-cyanopyridones via Hantzsch-like reaction using ammonium nitrate instead of the usually used ammonium acetate. Then we carried out several consecutive reactions on
these heterocyclic compounds to achieve the desired products: oxadiazolopyridines.
In the third chapter, we have prepared some dipeptide N-cyanopyridines from
cyanopyridines by carrying out some consecutive reactions.
