硫酸の存在下アセチレンジカルボン酸と硫酸の存在下アセチレンジカルボン酸とメタノールの反応で生成するエステルの定性とアミド化生成物

抄録

The characterization of the esters obtained from acetylenedicarboxylic acid monopotassium salt upon treatment with methanol in the presence of sulfuric acid and their characteristic behavior in the amidation with methanolic and aqueous ammonia are described. Under ordinary conditions, the mono-potassium salt gives dimethyl acetylenedicarboxylate(1a) together with an appreciable amount of higher boiling substances consisting of dimethyl α, α-dimethoxysuccinate (5a), dimethyl methoxymaleate (2b), and dimethyl methoxyfumarate (3b), in which the latter two predominate.The evidence most partinent in establishing the structure of the esters obtained above has been presented. Amidation of la with excess ammonia gives generally a mixture of acetylenedicarboxamide (1b), aminofumaramide (3d) and methyl α-aminofumaraminate (3e), and the composition is variable depending on the reac tion conditions applied, of which the reaction temperature governs the relative amounts of 1b and 3e, and that of 1b and 3d are affected essentially by the reac tion time. Since 1b is transformed quantitatively after prolonged contact with ammonia into 3d, it is clear that 3d is produced from the initially formed 1b .2b yields in methanolic ammonia methoxymaleamide (2d) and aminomaleimide (6). With aqueous ammonia, 3b affords methyl α-methoxyfumaramate (3c), which is converted on further amidation into 3e and 6 . The mechanism of formation of the products has been discussed on the bases of above results.