Leslie J
J Pharm Sci. 1979 May;68(5):639-42. doi: 10.1002/jps.2600680534.
The reaction of 1,3-dimethylphenobarbital (I) with 0.02-0.32 M KOH in aqueous methanol was studied. The barbiturate ring cleaved reversibly at the 1,6-position, forming a malonuric acid which was stable to further hydrolysis but which could readily recyclize to I. N,N-Dimethylethylphenylmalondiamide arose from decarboxylation of the carbamic acid formed by a 1,2-ring opening; this irreversible decarboxylation determined the diamide as the only final reaction product. The malonuric acid, which could be isolated in solid form, appeared as N-methyl-2-phenylbutyramide (GLC) following thermal decarboxylation and degradation of the acid. The I disappearance rate was biphasic, and the kinetics were consistent with the described reaction. The individual rate constants and the equilibrium constant for the reaction between I, the malonuric acid, and hydroxide were determined.
研究了1,3 - 二甲基苯巴比妥（I）与0.02 - 0.32 M氢氧化钾在甲醇水溶液中的反应。巴比妥酸环在1,6位可逆裂解，形成丙二尿酸，该丙二尿酸对进一步水解稳定，但可轻易再环化生成I。N,N - 二甲基乙基苯基丙二酰胺由1,2 - 环开环形成的氨基甲酸酯脱羧产生；这种不可逆脱羧反应决定了二酰胺是唯一的最终反应产物。丙二尿酸可以固体形式分离出来，在热脱羧和酸降解后，以N - 甲基 - 2 - 苯基丁酰胺（气相色谱法）形式出现。I的消失速率呈双相，其动力学与所描述的反应一致。测定了I、丙二尿酸和氢氧化物之间反应的各个速率常数和平衡常数。
