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Catalyst‐free one‐pot regioselective synthesis of benzo[ d ]imidazo[2,1‐ b ]thiazoles by heating or grinding
Author(s) -
Meena Kalawati,
Saroha Mohit,
Khurana Ishani,
Malik Amita,
Rai Pramod K.,
Khurana Jitender M.
Publication year - 2019
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.3702
Subject(s) - chemistry , dimedone , regioselectivity , catalysis , grinding , condensation , phenylglyoxal , organic chemistry , medicinal chemistry , metallurgy , biochemistry , physics , arginine , thermodynamics , materials science , amino acid
Eco‐friendly, efficient, and simple one‐pot catalyst‐free new procedures have been reported for the synthesis of benzo[ d ]imidazo[2,1‐ b ]thiazoles by condensation of phenylglyoxal, cyclic enolizable carbonyl compounds, and 2‐aminobenzothiazole at 80°C or by grinding the components at room temperature in glycerol. Cyclic enolizable carbonyl compounds employed in the protocol include dimedone, cyclohexa‐1,3‐dione, cyclopenta‐1,3‐dione, 5‐methylcyclohexa‐1,3‐dione, and 4‐hydroxy‐6‐methyl‐2‐pyrone. All the reactions were complete in ~30 min. The structures of all the products were confirmed by spectral data. The structures of compounds IVl and IVe have also been confirmed by X‐ray crystallographic studies. This protocol offers advantages such as short reaction time, easy workup, high yields and an environmentally benign methodology.