Rapid solution-phase syntheses of novel 3,5- and 3,6-disubstituted-2(1H -pyrazinones were developed through selective, sequential substitution of 2,5-dihalo-3-benzyloxypyrazine and 3,5-dihalo-2(1H -pyrazinonesintermediates.
Epistasis, the non-additive interaction of mutations at multiple loci, plays a major role when resistance to antibiotics requires the sequential substitution of multiple mutations.
A novel class of multifunctional and multinucleate chalcogen (selenium and tellurium) containing derivatives (1 10) has been developed based on sequential chloride substitution of 2,4,6-trichloro-1,3,5-triazine with chalcogen-bearing amines.
The APCN gels were synthesized by the sequential nucleophilic substitution reaction between activated halide terminated PCL and poly ethylene glycol) (PEG -based PEG -basedno ester) or poly(bis-acrylamide)-based poly(amido amine) prepolymer containing amine moieties in the backbone or side chain.
We report the remarkable effect of a small amount of poly 2-dimethyl amino ethyl methacrylate) (poly 2-dimethyl-poly(N-isopropyl aminoamidethylpolymethacrylateomPDMAtior and the sol fraction of amPDMA-b-poly N-isopropylPDMA-b-poly N-isopropyl sequential nucleoPDMA-b-poly N-isopropylction between activated halide terminated PDMA-b-poly N-isopropylacrylamidery amine funcopolymergarone or dexthen.
Within a previously identified phosphorylated region of the Y1 receptor C tail (Holliday et al., 2005), sequential Ala substitution of the six Ser/Thr residues presents decreased maximum β-arrestin2 binding without altering agonist potency in the BiFC assay.
Due to the limitations of short read sequence alignment, the analysis between N2 and CB4858 is limited to sequential base substitutions, indels, and putative inversions with a length of 2 bp.
The high proportions of observed sequential base substitutions [3.6% (476/13360)] and indels [24% (3206/13360)] in CB4856 are not consistent with expectations based on a hypothesis of independent adjacent polymorphisms.
Specifically, an alternative to sequential fixation of substitutions, compensatory substitutions (including instances when two individually deleterious substitutions are neutral when combined), being fixed at the same time, has been proposed by Kimura (1985, J. Genet 64: 7-19), with some evidence of this particular route of compensatory evolution found in tRNAs (Meer, 2010 Nature 464:279-82).
A variety of substituted tris(pyridyl) frameworks, as well as a pentakis(pyridine) system, are conveniently accessible in a one-pot synthesis, which consists of two sequential nucleophilic aromatic substitutions, employing substituted pyridine precursors.
A short series of 2-alkoxy-4-aminotrifluoropyridine derivatives was prepared from pentafluoropyridine in a single continuous flow process by sequential nucleophilic aromatic substitution.
