The stability of carboquone in alcohols. II. Kinetics and mechanisms of degradation of carboquone in methanol.
作者:AKIRA KUSAI、SEIGO UEDA
DOI:10.1248/cpb.34.1299
日期:——
The kinetics and mechanisms of the degradation of carboquone (CQ) in methanol were investigated.Eight peaks were observed as degradation products of CQ in high performance liquid chromatography, suggesting that the degradation process of CQ in methanol is rather complicated. However, conducting the reaction in proton-rich methanol and methylate-rich methanol made it clear that CQ is degraded in methanol through a combination of two mechanisms : methanolysis of the aziridine ring, which cleaved to a (2-methoxyethyl)amino group, and substitution of the aziridine ring by methylate. Further, some of the degradation products were obtained in pure form by this procedure.Due to the asymmetric structure of CQ, two kinds of mono aziridinyl-mono methoxyethyl-amino compounds and two kinds of mono aziridinyl-mono methoxy compounds are produced. Kinetic studies of these four compounds and 2, 5-bis(1-aziridinyl)-3, 6-dimethyl-1, 4-benzoquinone made it possible to assign their chemical structures. Their deduced structures were confirmed by mass spectroscopy and proton nuclear magnetic resonance spectroscopy.
对卡巴醌(CQ)在甲醇中的降解动力学和机制进行了研究。 高效液相色谱检测到CQ的降解产物有8个峰, 表明CQ在甲醇中的降解过程相当复杂。 但在质子丰富的甲醇和甲氧基阴离子丰富的甲醇中进行反应, 发现CQ是通过以下两种机制的组合在甲醇中降解的: 环氧化物环的甲醇解生成(2-甲氧基乙基)氨基,以及环氧化物环被甲氧基阴离子取代。 进而, 通过这种方法获得了一些纯的降解产物, 由于CQ的不对称结构, 生成了两种单环氧化物-单甲氧基乙氨基化合物和两种单环氧化物-单甲氧基化合物。 对这四种化合物和2, 5-双(1-环氧化物)吡啶-3, 6-二甲基-1, 4-苯醌的动力学研究使得可以指定它们的化学结构。 通过质谱和氢核磁共振谱验证了这些推导结构。