engleski

Synthesis and structural studies of C-5 aryl and C-6 alkyl-substituted pyrimidine derivatives

C-5 and C-6 disubstituted pyrimidine derivatives 2-7 were synthesized. Introduction of the aryl rings at C-5 of pyrimidine moiety in 5 and 6 was performed using palladium-catalysed Stille cross-coupling reaction. The novel C-6 fluorophenylalkylated 5-phenylpyrimidine derivative (7) was prepared by lithiation of 5-phenylpyrimidine (6) and subsequent reaction of thus obtained organolithium intermediate with p-fluoroacetophenone. The structures of 3, 4 and 6 were determined by X-ray crystal structure analysis. Both methoxy groups in these structures adopt a synperiplanar conformation with respect to the N1 and N3 atoms of the pyrimidine ring. The molecules of 3 and 4 are linked through weak Br• • • Br interactions into zig-zag chains. The molecules of 6 are assembled into layers by one C− H• • • O hydrogen bond, C− H• • •  and aromatic pi...pi stacking interactions.

C-5 aryl pyrimidines ; C-6 fluoroalkylated pyrimidines ; Stille reaction ; X-ray crystal structure analysis ; intermolecular interactions

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