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Pyridazines with heteroatom substituents in positions 3 and 5. 6 . S N reactions in position 5 of 2‐aryl‐5‐hydroxypyridazin‐3(2 H )‐ones
Author(s) -
Schober Bernt D.,
Megyeri Gabor,
Kappe Thomas
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.5570270301
Subject(s) - chemistry , heteroatom , electrophile , aryl , yield (engineering) , electrophilic substitution , nucleophile , medicinal chemistry , nucleophilic substitution , iodine , stereochemistry , organic chemistry , ring (chemistry) , alkyl , catalysis , materials science , metallurgy
Abstract The nucleophilic introduction of chloro‐ ( 2 ), azido‐ ( 4 ), (substituted) amino ( 3, 6 ), mercapto ( 10 ) and hydrazino‐groups ( 13 ) into 2‐aryl‐5‐hydroxypyridazin‐3(2 H )‐ones [3] is described. The 5‐aminopyridazin‐3(2 H )‐one ( 6 ) also reacts with activated malonates 8 [4] to give pyrido[2,3‐ d ]pyridazines 9 . Hydrazino compounds 13 can be treated with aldehydes to yield compounds 14 . Iodine can be introduced into position 4 of 5 ‐amino ‐(15 ) and 5‐hydroxypyridazin‐3(2 H )‐ones ( 17 ) by electrophilic substitution to afford compounds 18 .