Chain-ring-chain tautomerism in 2-aryl-substituted hexahydropyrimidines and 1H-2,3-dihydroperimidines.: Does it appear?

被引：32

作者：

Maloshitskaya, O

Sinkkonen, J

Ovcharenko, VV

Zelenin, KN

Pihlaja, K ^{[1
]}

机构：

[1] Univ Turku, Dept Chem, Struct Chem Grp, FIN-20014 Turku, Finland

[2] Russian Mil Med Acad, St Petersburg 194044, Russia

来源：

TETRAHEDRON | 2004年 / 60卷 / 32期

关键词：

diamines; tautomerism; pyrimidines; perimidines;

D O I：

10.1016/j.tet.2004.05.092

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A series of 2-aryl substituted hexahydropyrimidines and perimidines were synthesized from aromatic aldehydes and substituted 1,3-propanediamines or 1,8-naphthalenediamine. The H-1 and C-13 NMR spectra showed that 2-arylperimidines and 2-aryl-4,4,6-trimethylhexahydropyrimidines exist exclusively in ring forms even in DMSO solutions, whereas 2-aryl-4-methylhexahydropyrimidines undergo chain-ring-chain tautomerism with a good linear correlation between the ring-chain equilibrium constants (log K, where K=[ring]/[chain]) and the Hammett-Brown sigma(+) parameters of the aromatic substituents. 4,4,6-Trimethylhexahydropyrimidines underwent complete and irreversible ring opening in CF3COOH solutions giving two different chain forms. (C) 2004 Elsevier Ltd. All rights reserved.

引用

页码：6913 / 6921

页数：9

共 28 条

[1] THE CONDENSATION OF 2,4-DIAMINO-4-METHYLPENTANE WITH CARBONYL COMPOUNDS [J].