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Synthesis of nitrogen‐containing heterocycles. 5 . A new route to 5‐amino‐[1,2,4]triazolo[1,5‐ a ][1,3,5]triazine derivatives
Author(s) -
Miyamoto Yoshiko,
Yamazaki Chiji,
Matzui Megumi
Publication year - 1990
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.5570270606
Subject(s) - chemistry , acetonitrile , amine gas treating , triazine , nitrogen , tertiary amine , medicinal chemistry , organic chemistry
Abstract Treatment of certain diaminomethylenehydrazones 1 of aromatic carbonyl compounds with ethyl N ‐cyanoimidate ( 2 ) in acetonitrile in the presence of a tertiary amine at room temperature gives the corresponding amino( N ‐cyanoiminomethyl)aminomethylenehydrazones 3 in high yields. The intermediate 3 can readily be cyclized to the corresponding 5‐amino‐2,3‐dihydro[1,2,4]triazolo[1,5‐ a ][1,3,5]triazines 4 in moderate to good yields by brief heating in acetonitrile. When the reaction of diaminomethylenehydrazones 1 with ethyl N ‐cyanoimidate ( 2 ) is performed at reflux temperature in the presence of a tertiary amine, 5‐amino‐2,3‐dihydro[1,2,4]triazolo[1,5‐ a ]1,3,5]triazines 4 can be directly obtained in moderate yields. The yields of triazolotriazine produced by the one‐step synthesis are generally comparable or even higher than the overall yields from the two‐step procedure.