- Regioselectivity in the amination of azines: Reaction of pyrazine derivatives with O-mesitylenesulfonylhydroxylamine
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Treatment of 2-X-substituted pyrazines [X = H, Me, Et, Pr, i-Pr, t-Bu, MeCH(OH), H2N, AcNH] with O-mesitylenesulfonylhydroxylamine gave the corresponding 2-X- and 3-X-(1-amino)pyrazin-1-ium mesitylenesulfonates. 2-Alkylpyrazines (X = Me, Et, Pr, i-Pr) displayed a correlation between the logarithms of the concentration ratio of 2- and 3-substituted cations and substituent steric constants. Wider series of substituted pyrazines [X = H, Me, Et, Pr, i-Pr, MeCH(OH), H2N, AcNH] conformed to a multiparameter correlation between the logarithms of the concentration ratio of 2- and 3-substituted cations, on the one hand, and substituent constants σI, σR?, and E s?, on the other. The obtained data on the regioselectivity of amination of pyrazines were interpreted in terms of DFT/PBE/3Z quantum-chemical calculations. Pleiades Publishing, Ltd., 2011.
- Borodkin,Vorob'ev,Shakirov,Shubin
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experimental part
p. 889 - 896
(2011/10/02)
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- Regioselectivity in 2-X-pyrazine aminations by O-mesitylenesulfonylhydroxylamine
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The regioselectivity of 2-X-pyrazine aminations by O-mesitylenesulfonylhydroxylamine was studied experimentally and the results are discussed from the viewpoint of electronic and steric factors. DFT calculations are consistent with the reaction proceeding according to an SN2 mechanism.
- Borodkin, Gennady I.,Vorob'ev, Aleksey Yu.,Shakirov, Makhmut M.,Shubin, Vyacheslav G.
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supporting information; experimental part
p. 6779 - 6782
(2010/04/29)
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- Quinoline derivatives as neurokinin receptor antagonists
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The present invention relates to substituted quinoline hydrazides of Formula (I): wherein R1, R2, R3, R4, R5, X, Y and Z are defined herein, pharmaceutical compositions comprising them and their use in treating diseases mediated by neurokinin-2 and/or neurokinin-3 (NK-3) receptors. These compounds can thus be used in methods of treatment to suppress and treat such disorders.
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Page/Page column 38
(2009/04/24)
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- Reactions of N-Heteroarylformamide Oximes and N-Heteroarylacetamide Oximes with N,N-Dimethylformamide Dimethyl Acetal. Synthesis of 2-Methyl-s-triazoloazines and N-Methylcyanoaminoazines
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N-Heteroarylformamide oximes 3 (R = H) were converted with N,N-dimethylformamide dimethyl acetal (DMFDMA) into N-heteroaryl-N-methylcyanoamino compounds 5, as the main products.In some instances N-heteroarylcyanoamino compounds 4, cyanoimino compounds 7, and some other products, such as 9 and 10 were also formed.On the other hand, N-heteroarylacetamide oximes 3 (R = CH3) were cyclized under the same reaction conditions into 2-methyl-s-triazoloazines (6).N-Heteroarylacetamide O-methyl oximes 11 and 12 were prepared from the corresponding acetamidines 2 (R = CH3) and O-methylhydroxylamine.
- Stanovnik, Branko,Stimac, Anton,Tisler, Miha,Vercek, Bojan
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p. 577 - 583
(2007/10/02)
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