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Reaction of 3,6‐disubstituted 4‐nitropyridazine 1‐oxides with methanolic ammonia and liquid ammonia
Author(s) -
Sakamoto T.,
Van Der Plas H. C.
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.5570140515
Subject(s) - chemistry , adduct , ammonia , reagent , liquid ammonia , organic chemistry , oxide , medicinal chemistry , inorganic chemistry
Reaction of 3‐chloro‐6‐methyW‐nitropyridazine 1‐oxide ( 5 ) with methanolic ammonia at 0° led to a replacement of the chlorine atom by a methoxy group as well as by an amino group. Reaction of the 3‐methoxy‐6‐methyl‐4‐nitropyridazine 1‐oxide ( 6 ) with the same reagent led to amino‐demethoxylation; this replacement reaction was very slow. Attempts to perform these reactions with liquid ammonia failed. Pmr spectroscopy of solutions of compound 6 in methanolic ammonia revealed that no σ‐adduct was present. However in liquid ammonia a 1:1 σ‐adduct at C‐5 i.e. 12b was formed. 3,6‐Dimethoxy‐4‐nitropyridazine 1‐oxide (7) gave with methanolic ammonia an amino‐demethoxylation at C‐6. No σ‐adduct could be detected by pmr spectroscopy. However, in liquid ammonia convincing pmr data were obtained showing the presence of a 1:1 σ‐adduct at C‐5.