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Chemistry of thienopyridines. XXX. Elaboration of the substituent in 6‐cyanothieno[2,3‐ b ]pyridine
Author(s) -
Klemm L. H.,
Muchiri Daniel R.
Publication year - 1983
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.5570200656
Subject(s) - chemistry , pyridine , substituent , reagent , yield (engineering) , medicinal chemistry , alkoxide , sodium ethoxide , derivative (finance) , organic chemistry , catalysis , materials science , ethanol , metallurgy , financial economics , economics
Ten derivatives of thieno[2,3‐ b ]pyridine bearing substituents at the 6‐position are obtained from transformations which start with 6‐cyanothieno[2,3‐ b ]pyridine (2). Treatment of 2 with sodium alkoxide‐alkanol gives imidates (3) in ca. 85% yield. Methyl imidate 3a reacts, in turn, with ammonium chloride to produce a carboxamidine (84%), with 1,ω‐alkyldiamines to form cyclic amidines, and with Meldrum's acid to give an aminoester intermediate (4) (36%). Various reagents then convert 4 into the acetyl derivative (86%) (also obtained directly from 2), an unsaturated aminoester (6) (80%), and a β‐ketoester (7) (39%). Spectral data are reported for these compounds.