Premium
Synthesis of 4,10‐dihydro‐4,10‐dioxo‐1 H ‐[1]‐benzopyrano[3,2‐ b ]pyridine, 4,5‐Dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano[2,3–6]pyridine and 1,5‐Dihydro‐1,5‐dioxo‐4 H ‐[1]‐benzopyrano[3,4‐ b ]pyridine derivatives from aminobenzopyrones
Author(s) -
Connor David T.,
Young Patricia A.,
Von Strandtmann Maximilian
Publication year - 1981
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.5570180412
Subject(s) - chemistry , pyridine , hydrolysis , stereochemistry , medicinal chemistry , condensation , dimethyl acetylenedicarboxylate , organic chemistry , cycloaddition , catalysis , physics , thermodynamics
3‐Aminochromone and 3‐aminocoumarin were condensed with diethyl ethoxymethylenemalonate and with dimethyl acetylenedicarboxylate to give intermediates, which were thermally cyclized to give 4,10‐dihydro‐4,10‐dioxo‐l H ‐[1]‐benzopyrano[3,2‐ b ]pyridinecarboxylates and 1,5‐dihydro‐1,5‐dioxo‐4 H ‐[1]‐benzopyrano‐[3,4‐ b ]pyridinecarboxylates. 2‐Aminochromone was converted to 4,5‐dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano‐[2,3‐ b ]pyridinecarboxylate via an intermediate condensation product with diethyl ethoxymethylenemalonate. These esters were hydrolyzed to the corresponding carboxylic acids (21, 30, 36, 50, and 60). Attempts to prepare 4,5‐dihydro‐4,5‐dioxo‐1 H ‐[1]‐benzopyrano[4,3‐ b ]pyridinecarboxylates from 4‐aminocoumarin were unsuccessful.