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Studies on methoxylation in the 7 H ‐naphtho[1,2,3‐ I,j ][2,7]naphthyridin‐7‐one system
Author(s) -
Zjawiony Jordan K.,
Kbalil Ashraf A.,
Clark Alice M.,
Hufford Charles D.,
Buolamwini John K.
Publication year - 1997
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.5570340422
Subject(s) - chemistry , nucleophilic substitution , regioselectivity , bromine , ring (chemistry) , medicinal chemistry , substitution reaction , substitution (logic) , nucleophile , kinetic control , nucleophilic aromatic substitution , stereochemistry , organic chemistry , catalysis , computer science , programming language
Studies on methoxylation in the 7H‐naphtho[1,2,3‐ i,j ][2,7]naphthyridin‐7‐one (sampangine) system represented by 3‐bromo‐ and 4‐bromosampangine as well as sampangine itself are described. We have found that regioselectivity of nucleophilic substitution in the sampangine system can be directed by reaction conditions. Under kinetic control (lower temperatures) substitution at C‐4 is the predominant reaction, regardless of whether 3‐bromo or 4‐bromosampangine were used. At higher temperatures, when the reaction is thermodynamically controlled, substitution of the bromine atom at C‐3 predominates. This is the first reported example of nucleophilic substitution in ring A of the 7 H ‐naphtho[1,2,3‐ i,j ][2,7]naphthyridin‐7‐one system.