Enaminones in heterocyclic synthesis: A new regioselective synthesis of 2,3,6‐trisubstituted pyridines, 6‐substituted‐3‐aroylpyridines and 1,3,5‐triaroylbenzenes

Abstract

1‐Substituted‐3‐dimethylaminopropenones 1a‐d reacted with acetylacetone and with ethyl acetoacetate to yield regioselectively 2,3,6‐trisubstituted pyridines. Refluxing 1a‐d in acetic acid/ammonium acetate resulted in the formation of 6‐substituted‐3‐aroylpyridines, whereas refluxing in acetic acid alone afforded 1,3,5‐triaroylbenzene.

Design, synthesis and QSAR study of certain isatin-pyridine hybrids as potential anti-proliferative agents

“…The reaction mixture was heated under reflux for 5 h. After cooling and pouring into ice-water, the residue obtained was filtered and washed with petroleum ether then with water and finally crystallized from ethanol [51].…”

Crystal structure of 2-((dimethylamino)methylene)-5,5-Dimethylcyclohexane-1,3-dione, C11H17NO2

“…A mixture of 5,5-dimethylcyclohexane-1,3-dione (1.4 g, 0.01 mol) and dimethylformamide-dimethylacetal (DMF-DMA) (1.19 g, 0.01 mol) in dry xylene (20 mL) was re uxed for 2 h, the reaction mixture was cooled, and the obtained solid was recrystallized from ethanol to give the corresponding 2-(dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione [13]. Yield%: 71, m.p.…”

Lanthanum immobilized on chitosan: a highly efficient heterogeneous catalyst for facile synthesis of novel (α,β‐unsaturated) β‐aminoketones

“…[18][19][20][21] A few drawbacks associated with these protocols include the use of homogeneous and corrosive catalysts and limited substrate tolerance. [18,19] In this regard, protocols for the synthetic improvement of this reaction are still desirable. Hence, we have synthesized a novel lanthanum immobilized on chitosan (La/chitosan) and evaluated its catalytic activity for aza-Michael reaction.…”