456-14-4Relevant articles and documents
Facile synthesis of 3,5-diaryl-1,2,4-triazoles via copper-catalyzed domino nucleophilic substitution/oxidative cyclization using amidines or imidates as substrates
Sudheendran, Kavitha,Schmidt, Dietmar,Frey, Wolfgang,Conrad, Jürgen,Beifuss, Uwe
, p. 1635 - 1645 (2014/02/14)
Two methods for the synthesis of 3,5-diaryl-1,2,4-triazoles, both domino reactions, are reported. The first procedure, the Cu(OTf)2-catalyzed reaction between two amidines using NaHCO3 as a base, 1,10-phenanthroline as an additive and K3[Fe(CN)6]/ atmospheric oxygen as the oxidant, delivers 3,5-diaryl-1,2,4-triazoles with yields up to 68%. The second procedure for the synthesis of 3,5-diaryl-1,2,4- triazoles with yields up to 64% rests on the Cu(OTf)2-catalyzed reaction between two imidates and ammonium carbonate. This method features the formation of three bonds in a single synthetic step.
Pyrimidine derivatives and liquid crystal compositions including same
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, (2008/06/13)
2-phenyl-5-(4'-trans-cyclohexyl) phenyl pyrimidine derivatives represented by the general formula: STR1 wherein R is a straight chain alkyl group having 1 to 10 carbon atoms; X is CN or F; Y is F or H; Z is F or H; and when X is F, at least one of Y and Z is H; and the cyclohexane ring is a trans isomer, exhibiting a nematic phase and having a high nematic phase-isotropic liquid phase transition temperature (N-I Point) and large positive dielectric constant anisotropy (Δε). The pyrimidine derivatives may be included in liquid crystal compositions for improved display devices having a wide temperature range, including a high N-I point, a low threshold voltage and a low driving voltage.