Transnitrosation by N-Aryl-N-nitrosoureas; NO-Carrying O-Nitrosoisourea.
作者:Masayuki TANNO、Shoko SUEYOSHI、Naoki MIYATA
DOI:10.1248/cpb.42.1760
日期:——
Transfer of nitroso groups, so-called transnitrosation, from aromatic N-nitroso compounds such as N-nitrosoureas, N-nitrosamides and N-nitrosamines, to aromatic amines or ureas was observed under non-acidic conditions at room temperature. Sterically hindered 3, 3-dibenzyl-1-(4-tolyl)-1-nitrosourea (1a) rapidly nitrosates indoline, N-alkylanilines or 3-methyl-1-(4-tolyl)urea to give their N-nitroso derivatives. In the case of N, N-dimethylanilines, nitrosative demethylation occurs to give N-methyl-N-nitrosanilines. The transnitrosation is accelerated by electron-releasing groups on the nitroso acceptors, N-alkylanilines. The transnitrosation mechanism is considered to be as follows : N-nitrosourea (1) thermally decomposes to nitric oxide and ureidyl radical followed by formation of an O-nitrosoisourea intermediate (10), which acts as an NO-carrying agent and nitrosates anilines or ureas.
从芳香族N-亚硝基化合物(如N-亚硝基脲、N-亚硝基酰胺和N-亚硝基胺)向芳香族胺或脲转移亚硝基的过程,称为转亚硝基化,在室温下非酸性条件下被观察到。立体障碍的3, 3-二苯基-1-(4-甲基苯基)-1-亚硝基脲(1a)迅速与吲哚、N-烷基苯胺或3-甲基-1-(4-甲基苯基)脲发生亚硝化反应,生成其N-亚硝基衍生物。在N,N-二甲基苯胺的情况下,发生亚硝化去甲基化,生成N-甲基-N-亚硝基苯胺。转亚硝基化受到电子供体基团的促进,这些基团位于亚硝基接受体N-烷基苯胺上。转亚硝基化机制被认为如下:N-亚硝基脲(1)热分解生成一氧化氮和脲基自由基,随后形成O-亚硝基异脲中间体(10),后者作为NO载体,与苯胺或脲进行亚硝化。