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Chemical properties of N ‐Benzoylimines of quinazoline, quinoxaline, and phthalazine
Author(s) -
Tamura Yasumitsu,
Miki Yasuyoshi,
Nakamura Keiko,
Ikeda Masazumi
Publication year - 1976
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.5570130103
Subject(s) - chemistry , dimethyl acetylenedicarboxylate , medicinal chemistry , quinoxaline , acrylonitrile , cycloaddition , nucleophile , cyanate , adduct , hydroxide , quinazoline , sydnone , organic chemistry , ring (chemistry) , polymer , copolymer , catalysis
Reactions of 1‐benzoylimino‐4‐phenylquinazolinium (I), 1‐benzoylimino‐3‐phenylquinox‐alinium (II), and 3‐benzoylimino‐1‐phenylphthalazinium betaines (III) with nucleophiles (hydroxide and cyanide ions) and 1,3‐dipolarophiles (acetylenic esters and maleimides) were investigated. Heating I in aqueous alkali gave 3‐phenylindazole, while similar treatment of II and III resulted in the formation of 1‐benzoylamino‐2‐oxo‐3‐phenylquinoxaline and 2‐benzoylamino‐1‐oxo‐4‐phenylphthalazine, respectively. Reaction of II and III with cyanide ion afforded 2‐cyano‐3‐phenylquinoxaline and 1‐cyano‐4‐phenylphthalazine in high yields, respectively. 1,3‐Dipolar cycloaddition reactions of I and III with dimethyl acetylenedicarboxylate and ethyl propiolate afforded primary 1:1 cycloadducts, while the reaction of II with dimethyl acetylenedicarboxylate gave a product which is formed by ring opening of a primary adduct. The reaction of I‐III with N ‐methyl and N ‐phenylmaleimides afforded the corresponding primary 1:1 cycloadducts in high yields, whose stereochemical assignment was made on the basis of nmr spectroscopy.