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A Green Synthesis of 2‐Amino‐4‐(9 H ‐carbazole‐3‐yl)thiophene‐3‐carbonitriles by a Step‐wise and One‐pot Three‐component Gewald Reaction
Author(s) -
Avula Vijay Kumar Reddy,
Vallela Swetha,
Anireddy Jaya Shree,
Chamarthi Naga Raju
Publication year - 2017
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.2847
Subject(s) - malononitrile , carbazole , chemistry , thiophene , knoevenagel condensation , tetrahydrofuran , organic chemistry , arylene , condensation , sulfur , condensation reaction , combinatorial chemistry , catalysis , alkyl , physics , aryl , thermodynamics , solvent
An eco‐friendly method has been developed for the synthesis of 2‐amino‐4‐(9 H ‐carbazole‐3‐yl)thiophene‐3‐carbonitriles from preliminary carbazole ( 1 ) through an intermediate of 2‐(1‐(9 H ‐carbazole‐3‐yl)ethylidene)malononitriles using the Knoevenagel condensation followed by the Gewald reaction. On the other hand, the target compounds could also be prepared in a one‐pot three‐component manner by treating equimolar quantities of 1‐(9 H ‐carbazole‐3‐yl)ethanone ( 3 ), malononitrile, and elemental sulfur. The merits of this preparation are mild reaction conditions. The Gewald reaction is executed with inorganic base NaHCO 3 (H 2 O) in tetrahydrofuran, easy work‐up procedure with good yields.