Home | My Profile | Contact Us
Research Trends Products  |   order gateway  |   author gateway  |   editor gateway  
Register | Forgot Password

Author Resources
 Author Gateway
 Article submission guidelines

Editor Resources
 Editor/Referee Gateway

 Regional Subscription Agents/Distributors
Trends in Heterocyclic Chemistry   Volumes    Volume 12 
Regioselectivity of the chemical transformations of thio analogues of pyrimidine bases
Zdzisława Nowakowska, Elżbieta Wyrzykiewicz
Pages: 1 - 45
Number of pages: 45
Trends in Heterocyclic Chemistry
Volume 12 

Copyright © 2007 Research Trends. All rights reserved

Thio analogues of Pyrimidine Bases have occupied a unique place and have remarkably contributed to biological and medicinal chemistry. By reason of these biological and pharmacological activities the reactivity of the derivatives of thiouracils present a great interest in chemical investigations. Literature survey showed that the reaction of thio analogues  of pyrimidine bases (as 6-membered ambident heterocyclic systems) with various halo substituted organic compounds (alkyl and alkenyl halides or dihalides, benzyl halides, haloaldehydes,  halo-ketones, acetals of haloaldehydes, halocarboxylic acids halides and anhydrides, as well as esters of halocarboxylic acids) gave S-mono substituted, S-N1/N3 disubstituted or S-N1/N3 cyclized products (thiazolopyrimidediones, pyrimido-thiazinodiones etc.) which are of interest due to their biological activities. The regioselectivity of these methods of preparation of the modified derivatives of thio analogues of pyrimidine bases depends upon the structures of substrates and the conditions of the reactions (i.e. the stoichiometry, solvents, temperature, catalyst, time and basicity). These reactions can be kinetically or thermo-dynamically controlled. It is also known that some of these products can be synthetized in the reactions of direct cyclizations. The present review is concerned with providing the synthetic chemists with a critical survey which may facilitate the selection of practical experimental conditions to prepare selectively the regioisomers of which are of interest due to their structure, i. e. to control the regioselectivity in thio analogues of pyrimidine bases families. The characteristic features of the spectral analysis (UV/Vis, IR, 1H NMR, EIMS) one can be used for identifications of obtained isomers are also discussed.
Buy this Article


Buy this article
Buy this volume
Subscribe to this title
Shopping Cart

Quick Links
Search Products
Browse in Alphabetical Order : Journals
Browse by Subject Classification : Journals

Ordering Information Ordering Information
Downloadable forms Downloadable Forms