NEW METHOD FOR THE DETERMINATION OF THE RELATIVE ACIDITIES OF ALCOHOLS IN ALCOHOLIC SOLUTIONS - NUCLEOPHILICITIES AND COMPETITIVE REACTIVITIES OF ALKOXIDES AND PHENOXIDES
NEW METHOD FOR THE DETERMINATION OF THE RELATIVE ACIDITIES OF ALCOHOLS IN ALCOHOLIC SOLUTIONS - NUCLEOPHILICITIES AND COMPETITIVE REACTIVITIES OF ALKOXIDES AND PHENOXIDES
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DOI：
10.1139/v79-444
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发表时间：
1979-01-01
期刊：
影响因子：
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通讯作者：
ALUOTTO, PF
中科院分区：
文献类型：
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作者：
REEVE, W;ERIKSON, CM;ALUOTTO, PF
本文提出了一种新的半定量测定甲醇、乙醇、异丙醇和叔丁醇在混合羟基溶剂中相对酸度的方法。使两种醇的醇盐在过量的两种醇中的溶液与正丁基溴反应以形成两种醚的混合物。醚混合物的组成是两种醇盐的“竞争反应性”的量度。这可以直接测量，理论上可以分为两个部分：两种醇盐的相对亲核性和相对碱度。相对亲核性通过使用其中苯酚是一种组分的溶液来测定。已知竞争反应性和亲核性，甲醇、乙醇、异丙醇和叔丁醇在醇介质中的相对酸度分别为4.4、1.0、0.24和0.21。氢氧化物、甲醇盐、乙醇盐、异丙醇盐、叔丁醇盐、苯酚盐和间甲酚盐的相对亲核性分别为0.08、0.82、1.0、0.4、0.04、0.46和0.57。
A new semiquantitative method has been developed for measuring the relative acidities of methanol, ethanol, isopropyl alcohol, andtert-butyl alcohol in mixed hydroxylic solvents. A solution of the alkoxides of two alcohols in an excess of the two alcohols is allowed to react withn-butyl bromide to form a mixture of two ethers. The composition of the ether mixture is a measure of the "competitive reactivity" of thetwo alkoxides. This can be measured directly, and in theory can be factored into two components: the relative nucleophilicity and the relative basicity of the two alkoxides. Relative nucleophilicities are determined by using solutions in which phenol is one component. Knowing the competitive reactivities and nucleophilicities, the relative acidities of methanol, ethanol, isopropyl alcohol, andtert-butyl alcohol in alcoholic media are shown to be 4.4, 1.0, 0.24, and 0.21, respectively. The relative nucleophilicities of hydroxide, methoxide, ethoxide, isopropoxide,tert-butoxide, phenoxide, andm-cresoxide are 0.08, 0.82, 1.0, 0.4, 0.04, 0.46, and 0.57 respectively.