- The thermal instability of 2,4 and 2,6-N-alkylamino-disubstituted and 2-N-alkylamino-substituted nitrobenzenes in weakly alkaline solution: Sec-amino effect
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We report herein the preparation of two families of secondary amines by the reactions of two equivalents of monoamines with either 2,4 or 2,6-difluoronitrobenzenes in N,N-dimethylacetamide in the presence of anhydrous potassium carbonate, as precursors of biologically important nitric oxide donating N-nitrosamines. In both instances, these compounds could be prepared in quantitative yield when the reaction temperature was held below 130°C. Above this reaction temperature, an unexpected cyclization reaction between the nitro and newly formed adjacent secondary amine group leads to the formation of benzimidazole or quinoxaline rings in low yields. Reasonable reaction mechanisms for the cyclization reaction are proposed.
- Walczak, Christopher,Payne, Thomas J.,Wade, Colin B.,Yonkey, Matthew,Scheid, Melissa,Badour, Alec,Mohanty, Dilip K.
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p. 681 - 687
(2015/05/13)
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- 1,3-Bis(ethyl-amino)-2-nitro-benzene, 1,3-bis-(n-octylamino)-2-nitro- benzene and 4-ethylamino-2-methyl-1H-benz-imid-azole
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1,3-Bis(ethyl-amino)-2-nitro-benzene, C10H15N3O2, (I), and 1,3-bis-(n-octylamino)-2-nitro-benzene, C22H39N3O2, (II), are the first structurally characterized 1,3-bis-(n-alkyl-amino)-2-nitro-benzenes. Both mol-ecules are bis-ected though the nitro N atom and the 2-C and 5-C atoms of the ring by twofold rotation axes. Both display intra-molecular N - H...O hydrogen bonds between the amine and nitro groups, but no inter-molecular hydrogen bonding. The nearly planar mol-ecules pack into flat layers ca 3.4 A apart that inter-act by hydro-phobic inter-actions involving the n-alkyl groups rather than by π-π inter-actions between the rings. The intra- and inter-molecular inter-actions in these mol-ecules are of inter-est in understanding the physical properties of polymers made from them. Upon heating in the presence of anhydrous potassium carbonate in dimethyl-acetamide, (I) and (II) cyclize with formal loss of hydrogen peroxide to form substituted benzimidazoles. Thus, 4-ethylamino-2-methyl-1H-benzimidazole, C10H13N3, (III), was obtained from (I) under these reaction conditions. Compound (III) contains two independent mol-ecules with no imposed inter-nal symmetry. The mol-ecules are linked into chains via N - H...N hydrogen bonds involving the imidazole rings, while the ethylamino groups do not participate in any hydrogen bonding. This is the first reported structure of a benzimidazole derivative with 4-amino and 2-alkyl substituents.
- Walczak, Christopher P.,Yonkey, Matthew M.,Squattrito, Philip J.,Mohanty, Dillip K.,Kirschbaum, Kristin
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p. o248-o251
(2008/09/21)
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- Substituted propylamine derivatives and methods of their use
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The present invention is directed to substituted propylamine derivatives of formula I: or a pharmaceutically acceptable salt thereof, compositions containing these derivatives, and methods of their use for the prevention and treatment of conditions ameliorated by monoamine reuptake including, inter alia, vasomotor symptoms (VMS), sexual dysfunction, gastrointestinal and genitourinary disorders, chronic fatigue syndrome, fibromylagia syndrome, nervous system disorders, and combinations thereof, particularly those conditions selected from the group consisting of major depressive disorder, vasomotor symptoms, stress and urge urinary incontinence, fibromyalgia, pain, diabetic neuropathy, and combinations thereof.
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Page/Page column 34
(2010/11/26)
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