Organizing co mmittee

 
 
NH
2
+
H
3
CO
H
3
CO
O
O
+
CHO
R
C
2
H
5
OH
HN
H
3
CO
H
3
CO
O
O
OH
R

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Poster presentation 
287 
SYNTHESIS PYRROLES BASED ON β-DICARBONYL 
COMPOUNDS 
 
Z.O. Kilichev, A.B. Yusupov, D.B. Tukhtaev 
 
Samarkand State University, Samarkand, Uzbekistan 
e-mail: [e-mail]  
The pyrrole ring is found in plant chlorophylls - porphyrins, hemoglobin heme and 
cytochromes, as part of a number of important biologically active natural and synthetic 
compounds. Formation of a pyrrole ring is also very common in the synthesis of 
candidate biologically active compounds. Therefore, the effective synthesis of pyrroles 
and pyrrole ring compounds requires extensive research. The synthesis of pyrroles from 
β-dicarbonyl compounds under the conditions of the Paal-Knorr reaction is 
conventionally explained as consisting of two stages. Early stage enaminones 
themselves are one of the important intermediate compounds in organic synthesis. 
Enaminones are traditionally obtained by boiling β-dicarbonyl compounds and amines 
in aromatic solvents. The process requires the azeotropic removal of water from the 
reaction mixture, which is formed as a result of internal molecular dehydration. In 
addition, in recent years, a number of methods using various catalysts based on Lewis 
acids have been developed. However, condensation reactions in all cases involve 
complex processes involving high temperatures, toxic catalysts, and volatile organic 
solvents. 
In recent years, the presence of ultrasound has been widely used as a mild, efficient 
and highly selective method in organic synthesis. The method is also fully compatible 
with energy saving requirements. In our experiments, enaminones were initially 
obtained from the reaction of primary aromatic and heteroaromatic amines with β-
dicarbonyls under the influence of ultrasound. As a result of continued reactions with 
enaminones in the presence of a catalyst, suitable pyrrole derivatives were synthesized. 
In this case, the reaction temperature was much lower than traditional methods , and 
was lowered to 0-5
o
C. Due to the addition of ultrasound to the process, the duration of 
the reaction was reduced to 1-15 minutes. 
The reactions of 1,3-dicarbonyl compounds with new amines was carried out under 
ultrasonic conditions and the capability of aromatic and heteroaromatic amines in 
enamination reactions was compared. The selected method was found to be “green” and 
efficient for the synthesis of enaminones and pyrroles.