A cyclization of 1,2-bisureido compounds with sodium nitrite.
作者:MAKOTO MIYAHARA、MASAHIRO NAKADATE、MICHIKO MIYAHARA、IKUO SUZUKI
DOI:10.1248/cpb.26.2635
日期:——
Nitrosation of bisureido compounds with sodium nitrite in the presence of acid was examined. The treatment of 1, 2-bisureidoethane with sodium nitrite in 6% sulfuric acid, afforded 1-carbamoyl-3-nitroso-2-imidazolidinone in 86% yield. Similarly, the same nitrosation of 1, 2-bisureidopropane gave an isomeric mixture of cyclized N-nitroso compounds in 87% yield. On the other hand, nitrosation of o-phenylenebisurea with sodium nitrite and 25% sulfuric acid, gave only cyclized 1-carbamoyl-2-benzimidazolidinone in 58% yield, and nitroso compound was not obtained. This nitrosative cyclization occurs only in 1, 2-bisureido compounds which have no substituent in the ureido nitrogens. The mechanism of this cyclization was also discussed.
用酸性条件下的亚硝酸钠对双脲化合物进行亚硝化反应的研究。将1,2-双脲乙烷与6%硫酸中的亚硝酸钠反应,得到1-氨基-3-亚硝基-2-咪唑偶氮酮,产率为86%。类似地,1,2-双脲丙烷的亚硝化反应也得到了一混合物的环化N-亚硝基化合物,产率为87%。另一方面,使用亚硝酸钠和25%硫酸对邻苯二脲进行亚硝化反应,仅得到环化的1-氨基-2-苯并咪唑偶氮酮,产率为58%,而没有获得亚硝基化合物。该亚硝化环化反应只发生在不含取代基的1,2-双脲化合物中。本文还讨论了该环化反应的机制。