synthesis of new unsymmetrical 4,5-dihydroxy-2-imidazolidinones. dynamic nmr spectroscopic study of the prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone合成新的不对称4,5-dihydroxy-2-imidazolidinones。.pdfVIP

下载本文档

2
0
约3.29万字
约 8页
2017-09-12 发布于上海
举报
版权申诉

synthesis of new unsymmetrical 4,5-dihydroxy-2-imidazolidinones. dynamic nmr spectroscopic study of the prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone合成新的不对称4,5-dihydroxy-2-imidazolidinones。.pdf

1、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。。
2、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
3、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。
4、该文档为VIP文档，如果想要下载，成为VIP会员后，下载免费。
5、成为VIP后，下载本文档将扣除1次下载权益。下载后，不支持退款、换文档。如有疑问请联系我们。
6、成为VIP后，您将拥有八大权益，权益包括：VIP文档下载权益、阅读免打扰、文档格式转换、高级专利检索、专属身份标志、高级客服、多端互通、版权登记。
7、VIP文档为合作方或网友上传，每下载1次，网站将根据用户上传文档的质量评分、类型等，对文档贡献者给予高额补贴、流量扶持。如果你也想贡献VIP文档。上传文档

synthesis of new unsymmetrical 4,5-dihydroxy-2-imidazolidinones. dynamic nmr spectroscopic study of the prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5-dihydroxy-2-imidazolidinone合成新的不对称4,5-dihydroxy-2-imidazolidinones。

Molecules 2006, 11, 768-775 molecules ISSN 1420-3049 Full Paper Synthesis of New Unsymmetrical 4,5-Dihydroxy-2- imidazolidinones. Dynamic NMR Spectroscopic Study of the Prototropic Tautomerism in 1-(2-Benzimidazolyl)-3-phenyl-4,5- dihydroxy-2-imidazolidinone * Mehdi GhandiP P , Abolfazl Olyaei and Farshid Salimi School of Chemistry, University College of Science, University of Tehran, Tehran, Iran * P Author to whom correspondence should be addressed. E-mail: ghandi@khayam.ut.ac.ir; Tel.: (+98)-P 21 Fax: (+98)-21 Received: 28 September 2006; in revised form: 11 October 2006 / Accepted: 12 October 2006 / Published: 19 October 2006 Abstract: The acid-catalyzed cyclocondensation in refluxing acetonitrile of aqueous glyoxal with N-heteroaryl-N-phenylureas 4a-f (heteroaryl = 2-thiazolyl, 2-pyrimidinyl, 2-pyrazinyl, 2-pyridinyl, 3-pyridinyl and 2-benzimidazolyl) led to the formation of the corresponding 1-heteroaryl-3-phenyl-4,5-dihydroxy-2-imidazolidinones 5a-f. All the products were characterized by elemental and spectroscopic analyses. The free-energy ≠ barrier (∆GP P ) for prototropic tautomerism in 1-(2-benzimidazolyl)-3-phenyl-4,5- dihydroxy-2-imidazolidinone (5f) was determined by dynamic NMR studies to be 81 ± 2 -1 KJ molP P . Keywords: Dynamic NMR, N-Heteroaryl-N-phenylurea, 2-Imidazolidinone, Glyoxal. Introduction Synthesis of imidazolidines through the cyclocondensation of diami