نتایج جستجو برای: 5 trisubstituted imidazoles
تعداد نتایج: 1219018 فیلتر نتایج به سال:
A new and highly efficient methodology for the construction of synthetically important highly O-functionalized enantiopure 2,3,4-trisubstituted tetrahydrofurans with three contiguous stereocenters is reported.
The reaction of P-diketones 1 with phenyl hydrazine afforded 5-aryl-3-(1- methyl-5-nitro-2-imidazoly1)-1-phenylpyrazole (2) and 3-aryl-5-(1-methyl-5- nitro-2-imidazoly1) -1-phenylpyrazole (3). The reaction of diketones (1) with urea in the presence of p-toluenesulfonic acid gave 4-(or 6-)aryl-6-(or 4-)(1-methyl- 5-nitro-2-imidazolyl)-1-(lH)pyrimidones (4). The structures of all compounds w...
A microwave-assisted synthesis of 2-(4-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-1H-benzo[d]imidazoles from a phenylazide, propargyloxybenzaldehyde and a 1,2-diaminobenzene is proposed.
The supramolecular polymerization of pyrene imidazoles 1 and 2, governed by H-bonding and C-H···π interactions, yields aggregates showing the characteristic bluish emission pattern of pyrene-based monomers.
In nine strains of Clostridium innocuum, 3 beta-hydroxysteroid-dehydrogenating activities were detected. 3 beta, 7 alpha, 12 alpha-Trihydroxy- and 3 beta-hydroxy-12-keto-5 beta-cholanoic acids were identified as reduction products of the respective 3-keto bile acids by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. One strain was shown to contain a NAD-dependent 3 be...
The hypocholesterolemic activity for novel ureido fibrate analogues was found to be over 100-fold greater than for any "second-generation" fibrate in cholesterol-fed rats. A comparison of 12 related analogues revealed that the optimal configuration for a urea-bridging region located between two aromatic rings consisted of a trisubstituted nitrogen, optimally substituted with a C7 alkyl chain an...
Quaternisation of 3,5-diaryl-1,2,4-thiadiazoles with trimethylsilylmethyl triflate at 40 8C occurred at N-2. Separate desilylation of the salts resulted in a ring expansion to substituted 2H-1,3,5-thiadiazines 5. Heating of these with ethanolic sodium ethoxide caused sulfur extrusion and ring contraction to 2,4-disubstituted imidazoles 6. 3,4-Diaryl1,2,5-thiadiazoles were less reactive to alkyl...
A facile synthesis of optically active mono and trisubstituted calix[4]arenes is described wherein the chirality at the methylene bridges arises from centers of chirality present in the diyne and the bis-carbene complex from which they are constructed.
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