5-Pyrimidylboronic acid and 2-methoxy-5-pyrimidylboronic acid 4 have been synthesised by lithium-halogen exchange reactions on 5-bromopyrimidine and 2-methoxy-5-bromopyrimidine, respectively, followed by reaction with triisopropylborate. Suzuki cross-coupling reactions of 2 and 4 with heteroaryl halides [Na(2)CO(3), Pd(PPh(3))(2)Cl(2), 1,4-dioxane, 95 degrees C] yield heteroarylpyrimidines (heteroaryl = thienyl, quinolyl and pyrimidyl). Two-fold reaction of 2 with 4,6-dichloropyrimidine 12 gave 4,6-bis(5-pyrimidyl)pyrimidine 8(56% yield). Reaction of 4,6-dichloropyrimidine with 2-methoxy-5-pyridylboronic acid gave 4,6-bis(2-methoxy-5-pyridyl)pyrimidine 14 (84% yield). Conversion of into 4,6-bis(2-chloro-5-pyridyl)pyrimidine 15 (63% yield) followed by two-fold Suzuki reaction with 4-tert-butylbenzeneboronic acid gave the penta-arylene derivative 4,6-bis[2-(4-tert-butyl)phenyl-5-pyridyl]pyrimidine 16 (16% yield). Analogous reaction of 12 with 2-methoxy-3-pyridylboronic acid 17 gave 4,6-bis(2-methoxy-3-pyridyl)pyrimidine 18 (64% yield). The X-ray crystal structures of compound 2.0.5H(2)O and compound 18 are reported. The two hydroxyl H atoms in 2 have the usual exo-endo orientation. However, unlike most arylboronic acids, molecule 2 does not form a centrosymmetric hydrogen-bonded dimer. In molecule 18, the pyridine rings form dihedral angles of 39.9 degrees and 22.8 degrees with the central pyrimidine ring.
The synthesis of four novel organosulfur donors carrying two or more hydroxymethyl groups are described. TTF nuclei are fused to 1,4-dithiepine and/or 1,4-dithiine rings and in two cases both outer rings carry functionality capable of introducing hydrogen bonding; for the two chiral organosulfur donor molecules both racemic and enantiopure forms are prepared. † The synthetic details for the preparation of 34 are available as supplementary data. For direct electronic access see
Efficient syntheses of boronic acids (II) and (VIII) are reported and their title cross-coupling reactions are described. As a complementary approach to dipyridiyl pyrimidines, new reactions of pyridylboronic acids (X) and (XV) with pyrimidine (V) are performed. -(SAYGILI, N.; BATSANOV, A. S.; BRYCE*, M. R.; Org. Biomol. Chem. 2 (2004) 6, 852-857; Dep. Chem., Univ. Durham, Durham DH1 3LE, UK; Eng.) -Klein 31-129
Oxazolidinethione compounds were synthesized starting from racemic and enantiopure β‐amino alcohols. The molecular structure of oxazolidinethione 6a was elucidated by single‐crystal x‐ray crystallography. Oxazolidinethione compounds screened for antimicrobial activity showed mild minimum inhibitory concentration values.
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