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

Molecules

Mehdi GhandiPP¹  Abolfazl Olyaei² 

[1] id="af1-molecules-11-00768">School of Chemistry, University College of Science, University of Tehran, Tehran, Ir

关键词: Dynamic NMR;    -phenylurea"'>N-Heteroaryl-N'-phenylurea;    2-Imidazolidinone;    Glyoxal;   

DOI  :  10.3390/11100768

来源: mdpi

【 摘 要 】

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 (∆G^≠) 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 KJ mol^-1.

【 授权许可】

Unknown   
© 2006 by MDPI (http://www.mdpi.org).