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Chapter-5
Synthesis of highly substituted pyrroles
A three-component reactions of arylacyl bromides, amines, and dialkyl
acetylene dicarboxylate in the presence of iron(III) chloride as a catalyst at room
temperature afforded polysubstituted pyrroles in high yields (Figure-24). 42
Ar
O
H 2 N R
Br + or
NH 4 OAc
R
+ 1 O 2 C
CO 2 R 1
15 mol - % FeCl 3
CH 2 Cl 2 , rt, 14-16 h
CO 2 R 1
Ar N
CO 2 R 1
R
Figure-24
A new and efficient three-component reaction between dialkyl acetylene
dicarboxylates, aromatic amines, triphenylphosphine, and arylglyoxals afforded
polysubstituted pyrrole derivatives in high yields (Figure-25). The reactions were
performed in dichloromethane at room temperature and under neutral conditions. 43
Figure-25
Department of Chemistry, Saurashtra University, Rajkot-360005 166