Synthesis of .beta.-substituted pyrroles via 1-(pyrrol-2-ylmethylene)pyrrolidinium salts
Synthesis of .beta.-substituted pyrroles via 1-(pyrrol-2-ylmethylene)pyrrolidinium salts
复制标题
通过1-(吡咯-2-基亚甲基)吡咯烷鎓盐合成β-取代的吡咯
DOI：
10.1021/jo00806a037
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发表时间：
1971
影响因子：
3.6
通讯作者：
P. Sonnet
中科院分区：
文献类型：
--
作者：
P. Sonnet
用分光光度法测得25的巯基的p值为4.75。HARRAP9报告了20时的值为4.8±0.1。从4-硝基硫酚(在40%乙醇中为30时为4.77)和3-巯基苯甲酸(在水中为28时为6.15)的记录值10中，很明显，正如预期的那样，硝基增加了硫酚的酸度，而羧基增加了硫酚的酸度。2，2‘-和4，4’-二硫代联吡啶及其硝基和羧基衍生物呈现完全平行的情况，它们都被Grassetti和Murray7‘11推荐作为Ellman试剂的替代品。艾伯特和巴林12已经证明，由于共振，2-和4-硫代吡啶是不常见的酸性硫醇
The p for the sulfhydryl group at 25, determined spectrophotometrically, was found to be 4.75. Harrap9 has reported a value of 4.8±0.1 at 20. From the recorded values10 for 4-nitrothiophenol (4.77 at 30 in 40% aqueous ethanol) and for 3-mercaptobenzoic acid (6.15 at 28 in water) it is clear, as was expected, that the nitro group increases the acidity of thiophenol considerably more than does the carboxyl group. An exactly parallel situation is presented by 2, 2'-and 4, 4'-dithiodipyridine and their nitro and car boxy derivatives, all of which have been recommended by Grassetti and Murray7’11 as alternatives to Ellman’s reagent for the determination of sulfhydryl. Albert and Barlin12 have shown that 2-and 4-mercaptopyridine are uncommonly acidic thiols, by reason of the resonance