Synthesis 2011(21): 3496-3506  
DOI: 10.1055/s-0030-1260224
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Suzuki-Miyaura and Negishi Approaches to a Series of Forensically Relevant Pyridines and Pyrimidines

Dariusz Błachutb, Joanna Szawkałoa, Zbigniew Czarnocki*a
a Faculty of Chemistry, Warsaw University, Pasteura 1, 02-093 Warsaw, Poland
Fax: +48(22)8225996 ; e-Mail: czarnoz@chem.uw.edu.pl;
b Forensic Laboratory, Internal Security Agency, 1 Sierpnia 30A, 02-134 Warsaw, Poland
Further Information

Publication History

Received 10 June 2011
Publication Date:
13 September 2011 (online)

Abstract

A library of 5-aryl-4-methylpyrimidines, phenyl ring-substituted derivatives of 4-benzylpyrimidines, 2,6-benzylpyridines, and 2,6-dibenzyl-4-methylpyridines were prepared. The synthesis of 5-aryl-4-methylpyrimidines was accomplished by Suzuki­-Miyaura cross-coupling reaction between arylboronic acids and 5-bromo-4-methylpyrimidine. The 4-benzylpyrimidines and 2,6-benzylpyridines were synthesized by treatment of 4-bromopyrimidine and 2,6-dibromopyridine derivatives with ring-substituted benzylzinc reagents.

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The outcome of the reactions was controlled by GC-MS. The advantage of the GC-MS method is that it can be applied to complicated mixtures of compounds, providing useful information of their composition and the products ratio. Obviously, the differences in the mass spectra of closely related isomers cannot be spectacular but due to a similar fragmentation routes, the total ion current should be similar for substrate, final products and by-products formed. Consequently, the intensities (peak area) of the peaks in chromatograms are a good measure for the proportion of substances in the mixture. In our case, the conversion was calculated by comparison of the peak area of remaining substrate with a sum of peak areas of the final product and by-products. The yield of a particular component was calculated by comparing of a peak area of the product with a sum of peak areas recorded for remaining products and substrate (if present).

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Unpublished results.