کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5220032 1383375 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
N-Alkylation of N-arylsulfonyl-α-amino acid methyl esters by trialkyloxonium tetrafluoroborates
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
N-Alkylation of N-arylsulfonyl-α-amino acid methyl esters by trialkyloxonium tetrafluoroborates
چکیده انگلیسی

In this work we present the results obtained for the N-alkylation of a series of N-arylsulfonyl-α-amino acid methyl esters bearing different substituents at the 4-position of the sulfonamide aromatic ring. In particular, we compare the reactivity of these species with diazomethane and trimethyloxonium tetrafluoroborate in N-methylation processes. Diazomethylation is unsuccessful for N-arylsulfonamide derivatives containing electron-releasing groups on the aromatic ring. In these cases trimethyloxonium tetrafluoroborate is the reagent of choice for the direct and quantitative N-methylation. Further we extend our evaluation to the use of triethyloxonium tetrafluoroborate. This reagent shows to be very efficient in order to prepare N-ethyl derivatives of N-arylsulfonyl-α-amino acid methyl esters. An experimental protocol similar to that used for N-methylation with trimethyloxonium tetrafluoroborate is applied for the N-ethylation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron - Volume 67, Issue 50, 16 December 2011, Pages 9708-9714
نویسندگان
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