Preferential Protonation and Methylation Site of Thiopyrimidine Derivatives in Solution: NMR Data

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• 作者：Artem V. Kozlov ; Vyacheslav E. Semenov ; Anatoliy S. Mikhailov ; Albert V. Aganov ; Michael B. Smith ; Vladimir S. Reznik ; Shamil K. Latypov
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：March 13, 2008
• 年：2008
• 卷：112
• 期：10
• 页码：3259 - 3267
• 全文大小：201K
• 年卷期：v.112,no.10(March 13, 2008)
• ISSN：1520-5207

文摘

Protonation (alkylation) sites of several thiopyrimidine derivatives were directly determined by ¹H-¹⁵N (¹H-¹³C) heteronuclear single quantum coherence/heteronuclear multiple bond correlation methods, and it wasfound that in all compounds, protonation (methylation) occurred at the N1 nitrogen. GIAO DFT chemicalshifts were in full agreement with the determined tautomeric structures. According to ab initio calculations,the stability of the different protonated forms and methylated derivatives was favored due to thermodynamiccontrol and not kinetic control.