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Comparative Study of the Chemoselectivity and Yields of the Synthesis of N ‐Alkyl‐4‐(trihalomethyl)‐1 H ‐pyrimidin‐2‐ones
Author(s) -
Zanatta Nilo,
Faoro Débora,
da S. Fernandes Liana,
Brondani Patrícia B.,
Flores Darlene C.,
Flores Alex F. C.,
Bonacorso Helio G.,
Martins Marcos A. P.
Publication year - 2008
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200800822
Subject(s) - chemoselectivity , chemistry , alkylation , methyl iodide , alkyl , allyl bromide , bromide , iodide , organic chemistry , nuclear magnetic resonance spectroscopy , medicinal chemistry , catalysis
This paper reports a comparative study of the chemoselectivity and yields of the synthesis of N ‐alkyl‐4‐(trihalomethyl)‐1 H ‐pyrimidin‐2‐ones carried out by the cyclocondensation of 4‐alkoxy‐1,1,1‐trihalo‐3‐alken‐2‐ones (enones) with methyl‐ and allylureas with the N ‐alkylation of 4‐(trihalomethyl)‐1 H ‐pyrimidin‐2‐ones with methyl iodide and allyl bromide. To determine the chemoselectivity of the products obtained, all compounds were fully analyzed by 1 H and 13 C NMR and 2D HMBC spectroscopy. This study has demonstrated that the cyclocondensation reactions give better yields and furnish either N 1 ‐ or N 3 ‐alkylated products depending on both the reaction conditions and the substituents on the enones, whereas the alkylation of pyrimidin‐2‐ones gives lower overall yields and either an N 1 ‐alkylated product or a mixture of N 1 ‐ and O ‐alkylated products.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)