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A novel pentacyclic pyridine dilactone. 7‐methyl[1]benzopyrano[4,3‐ d ][1]benzoxacino[4,3‐ b ]pyridine‐6,16‐dione
Author(s) -
Rajyalakshmi K.,
Srinivasan V. R.
Publication year - 1980
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.5570170820
Subject(s) - chemistry , pyridine , coumarin , salicylaldehyde , acetic acid , ammonia , medicinal chemistry , bicyclic molecule , acetic anhydride , stereochemistry , organic chemistry , catalysis , schiff base
When equimolar quantities of salicylaldehyde 2 and ethyl 3‐amino‐2‐butenoate 3 or its constituents (ethyl 3‐oxobutanoate and ammonia) were refluxed on a steam‐bath for 6 hours with a trace of acetic acid, two products, a pentacyclic pyridine dilactone 4 and 3‐acetyl coumarin 5 , resulted in 15% and 45% yields, respectively. The structure of 4 was elucidated as 7‐methyl[1]benzopyrano[4,3‐ d ][1]benzoxacino[4,3‐ b ]‐pyridine‐6,16‐dione on the basis of its spectral data. The mechanism of its formation has been discussed. The reaction has been extended to three more substituted salicylaldehydes.