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The synthesis of proximal ‐benzolumazine, proxirnal ‐benzoxanthine, proximal ‐benzotheophylline and proximal ‐benzocaffeine
Author(s) -
Schneller Stewart W.,
Christ William J.
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.5570180347
Subject(s) - chemistry , yield (engineering) , stereochemistry , crystallography , metallurgy , materials science
The synthesis of pyrazino[2,3‐ f ]quinazolin‐8,10‐(7 H ,9 H )dione( proximal ‐benzolumazine, 1 ), imidazo[4,5‐ f ]‐quinazolin‐7,9‐(6 H ,8 H )‐dione ( proximal ‐benzoxanthine, 2 ), 6,8‐dimethylimidazo[4,5‐ f ]‐quinazolin‐7,9‐(6 H ,8 H ) dione ( proximal ‐benzotheophylline, 3 ), and 1,6,8‐trimethylimidazo[4,5‐ f ]quinazolin‐7,9‐(6 H ,8 H )dione ( proximal ‐benzocaffeine, 4 ) is reported by commencing with 2‐amino‐6‐chlorobenzamide and proceeding via a variety of 5,6‐disubstituted‐2,4‐(1 H ,3 H )quinazolinediones. Methylation of 3 is shown to yield 3,6,8‐trimethylimidazo[4,5‐ f ]quinazolin‐7,9‐(6 H ,8 H )dione ( 15 ) and 4 in a ratio of 4:1.