Relationship between pKa (H_2O) of 5-Substituted-4-amino-2-methylpyrimidines and Half Neutralization Potential and the Behavior of the Compounds in Nonaqueous Solvents
スポンサーリンク
概要
- 論文の詳細を見る
The potentiometric titrations of 5-substituted-4-amino-2-methylpyrimidines were examined as a base in various nonaqueous solvents. The quantitative determinations were effectively carried out in acidic and dipolar aprotic solvents. The potentials at half neutralization point (HNP values) were used as a measure of the relative basicity of the pyrimidines in the solvents. The values in each of the solvents could be lineally correlated with the pKa (H_2O) values and the Hammett's σ_m for the 5-substituents. Some of the pyrimidines which deviated considerably from these linear relationships were discussed. Moreover, it was found that the differentiating titration of a mixture of pyrimidines might be facilitated with increasing of the reaction constant of the Hammett's equations. On the other hand, it was indicated by the Hammett's equations and by comparison of ultraviolet absorption spectra that these pyrimidines existed largely as the amino form in the solvents as well as in water and the actual proton acceptor in these molecules was the 1-position of pyrimidine ring.
- 公益社団法人日本薬学会の論文
- 1966-12-25
著者
-
水上 聰
Shionogi Research Laboratory Shionogi And Co. Ltd.
-
平井 瑛三
Shionogi Research Laboratories Shionogi & Co. Ltd.
-
平井 瑛三
Shionogi Research Laboratories Shionogi And Co. Ltd.
関連論文
- Equilibrium Studies of 5-Substituted 4-Hydroxy-2-methylpyrimidines. VI. Ethereal Solvents Effect on the Lactim-Lactam Tautomerism
- Equilibrium Studies of 5-Substituted 4-Hydroxy-2-methylpyrimidines. V. Lactim-Lactam Tautomerism in Ethereal Solvents
- Application of Fluorescent Triazoles to Analytical Chemistry. I. Determination of Aromatic Primary Amine with 2,4,6-Triaminopyrimidine as a Reagent
- Studies on Sulfonamide Derivatives as Analytical Reagent. I. 2'-Mercapto-sulfonanilide Derivatives
- Ion Pair Extraction of Trimethoprim with Sulfonphthalein Dyes
- Studies on Thiohydroxamic Acids and Their Metal Chelates. IV. Reaction of Thiohydroxamic Acids with Metal Ions
- Studies on Thiohydroxamic Acids and Their Metal Chelates. III. Syntheses of Some Thiohydroxamic Acid Derivatives and Their Structures
- Studies on Thiohydroxamic Acids and Their Metal Chelates. II. Structures of Thiohydroxamic Acids
- Studies on Thiohydroxamic Acids and Their Metal Chelates. I. Syntheses of Thiohydroxamic Acids and O-Methyl-thiohydroxamic Acids
- A New Fluorometric Method for Latamoxef in Biological Materials Using 2,6-Diamino-3-nitrosopyridine