Synthesis of Pyridazine Derivatives. VIII. N-Oxidation of 3,4-Dimethylpyridazine Derivatives.

元データ 1963-06-25 公益社団法人日本薬学会


N-Oxidation of 6-chloro-3,4-dimethylpyridazine afforded two kinds of product (V and VI), the latter being in a very low yield. 6-Methoxy-3,4-dimethylpyridazine gave sole N-oxide (VIII). Catalytic dehalogenation of V and VI yielded 3,4-dimethylpyridazine N-oxide, II from V and III from VI respectively, both II and III being also obtained by N-oxidation of 3,4-dimethylpyridazine. V was derived to VIII. N-Oxide group in II, V and VIII was concluded to be in the position adjacent to the methyl group from the derivation of V into 1,3,4-trimethyl-6 (1H)-pyridazinone 2-oxide (X) by hydrolysis with dilute sodium hydroxide, followed by methylation with dimethyl sulfate and dilute alkali hydroxide. The structure of X was confirmed by the formation of 1,3,4-trimethyl-6 (1H)-pyridazinone (XI) by catalytic reduction which was prepared by methylation of 3,4-dimethyl-6 (1H)-pyridazinone. Consequently, the nitrogen further removed from the methyl group is oxidized in III and VI.


中込 孟也 Research Department, Pharmaceutical Division, Sumitomo Chemical Co., Ltd.
中込 孟也 Research And Development Center Pharmaceuticals Division Sumitomo Chemical Co. Ltd.