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Preparation of azolopyridazinecarboxylic acids
Author(s) -
Heinisch G.,
Lötsch G.,
Offenberger S.,
Stanovnik B.,
Tisler M.
Publication year - 1989
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.5570260643
Subject(s) - chemistry , regioselectivity , pyridazine , scope (computer science) , organic chemistry , medicinal chemistry , combinatorial chemistry , catalysis , computer science , programming language
Oxidation reactions of various methyl substituted azolopyridazines 2a‐d, 3a‐h, 4a,b were investigated in order to gain access to the title compounds. This procedure was found to be of limited scope affording only the carboxylic acids 5, 7 and 9. A variety of novel azolopyridazinecarboxylic acid methyl esters bearing one or two methoxycarbonyl groups at the pyridazine core 17,18 and 12,14,16, 20 , respectively, however, could be prepared by means of a regioselective radical substitution process.