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Synthesis and reactivity of 1,2,4‐triazolo[1,5‐ c ]quinazolines
Author(s) -
Pfeiffer WolfDiethard,
Bodtke Anja,
Mücke Jana,
Hetzheim Annemarie,
Pazdera Pavel
Publication year - 1999
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.5570360536
Subject(s) - chemistry , quinazoline , hydrazine (antidepressant) , hydrate , nitrous acid , carboxylic acid , reactivity (psychology) , medicinal chemistry , stereochemistry , organic chemistry , medicine , alternative medicine , chromatography , pathology
The preparation of 1,2,4‐triazolo[1,5‐ c ]quinazolines 4a‐d , 5 , 8a‐d by cyclocondensation of 1a‐c with carboxylic acids and carboxylic anhydrides, respectively, is described. By different pathways, the 5‐thioxo‐5,6‐dihydro‐1,2,4‐triazolo[1,5‐ c ]quinazolines 4a‐d react with hydrazine hydrate or amines with the formation of 5‐substituted 1,2,4‐triazolo[1,5‐ c ]quinazolines 9 and 10a‐d . Cyclocondensation of 9 with carboxylic acids, carboxylic anhydrides, and nitrous acid, respectively, leads to the new anellated heterocycles bis‐1,2,4‐triazolo[4,3‐ a :1,5‐ c ]quinazoline 13 and tetrazolo [1,5‐ a ]‐1,2,4‐triazolo[1,5‐ c ]quinazoline ( 14 ).