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Pyrimidine derivatives and related compounds VI. A novel synthesis of 3,5‐diacetamidopyrazole and of 2‐aminopyrazolo [1,5‐α] pyrimidines
Author(s) -
Fanagdi Mohamed Hilmy,
Kandeel Ezzat Mohamed,
Zayed Ezzat Mohamed,
Kandil Zaghtoul Flshahat
Publication year - 1977
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.5570140132
Subject(s) - chemistry , pyrimidine , sulfuric acid , acetic acid , derivative (finance) , medicinal chemistry , stereochemistry , organic chemistry , financial economics , economics
3,5‐Diaeetamidopyrazole (2) could be prepared via arylazo group decoupling from 3,5‐diamino‐4‐arylazopyrazoles ( 1a‐c ) by the action of acetic acid‐sulfuric acid mixture. Arylazo group removal could also be effected when 2‐amino‐5‐melhyl‐7‐oxo‐6,7‐dihydro‐3‐phenylazopyrazolo‐[1,5‐α]pyrimidine ( 5 ) was similarly treated. The 2‐aminopyrazolo[1,5‐α]pyrimridine derivative was obtained in this case. On the other hand, under the same experimental conditions compounds 7a‐c and 8 were recovered almost unaffected. The mechanism of the reaction is discussed.