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Pyridazines. XXXV . Preparation of some novel pyrimido[4,5‐ c ]pyridazine derivatives from 3‐alkylamino‐ and 3‐arylamino‐4‐pyridazinecarboxamides
Author(s) -
Haider Norbert,
Heinisch Gottfried,
Laßnigg Doris
Publication year - 1988
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.5570250117
Subject(s) - pyridazine , chemistry , combinatorial chemistry , stereochemistry , medicinal chemistry
Facile syntheses of pyrimido[4,5‐ c ]pyridazine‐5,7(6 H ,8 H )diones 4 , pyrimido[4,5‐c]pyridazin‐5(8 H )‐ones 7–10 , and dihydropyrimido[4,5‐ c ]pyridazin‐5(6 H )ones 5,6 starting from 3‐chloro‐4‐pyridazinecarbonitrile 1 via aminocarbonitriles 2 and aminocarboxamides 3 are described. In addition, a convenient access to the new aminopyridazinecarbonitrile 11 from the chloronitrile 1, employing the tetrazolo[1,5‐ b ]pyridazine 12 as the key intermediate, is reported.