The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane（DMNNDO） was improved by using tri（hydroxymethyl）nitromethane and acetone as starting materials through a ＂one-pot＂ method combined with alkali...The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane（DMNNDO） was improved by using tri（hydroxymethyl）nitromethane and acetone as starting materials through a ＂one-pot＂ method combined with alkaline hydrolysis and nitrosation reactions. The yield of DMNNDO was increased from 37% to 45%. The structure of DMNNDO was characterized by IR,^1H NMR,^13 C NMR,and elemental analysis. Also the thermal decomposition of DMNNDO was studied by using DSC and TG-DTG to find that there are primarily two exothermic decomposition processes between 90 and 300 oC. The crystal structure of DMNNDO was studied by X-ray single-crystal diffraction for the first time. The molecular structure exists as a dimeric form due to the presence of nitroso group. The crystal belongs to monoclinic system,space group C2/c with a = 14.515（3）,b = 9.955（2）,c = 11.897（2） °,β = 98.500（3）°,V = 1.6998（2） nm^3,Z = 8,D_c = 1.486 g×cm^-3,μ = 0.128 mm^-1,F（000） = 800,S = 1.055,R = 0.0358 and wR = 0.0917. In particular,DMNNDO could be easily hydrolyzed in hydrous systems and the hydrolysis mechanism in CDCl_3 was revealed by means of NMR monitoring.展开更多
Eight new Schiff bases of 5-nitro and 5-bromo-substituted 1,10-phenanthroline-2,9-dicarboxaldehydes with sulfur-containing amines, thiosemicarbazide, S-alkyl/aryl dithiocarbazates and 2-mercaptoaniline have been synth...Eight new Schiff bases of 5-nitro and 5-bromo-substituted 1,10-phenanthroline-2,9-dicarboxaldehydes with sulfur-containing amines, thiosemicarbazide, S-alkyl/aryl dithiocarbazates and 2-mercaptoaniline have been synthesized and characterized by a variety of spectroscopic methods. The condensation reactions of the dialdehydes with the amines were carried out both in the presence and absence of conc. sulfuric acid. A significant increase in yield of the Schiff bases was observed when the reactions were carried out in the presence of sulfuric acid.展开更多
Schiff bases are known to possess anticancer, antibacterial, antifungal, antitubercular, anti-inflammatory, antimicrobial and antimalarial properties. In this paper antibacterial studies against variety of plants and ...Schiff bases are known to possess anticancer, antibacterial, antifungal, antitubercular, anti-inflammatory, antimicrobial and antimalarial properties. In this paper antibacterial studies against variety of plants and human pathogenic bacteria with eight newly synthesized Schiff bases and several intermediate silyl compounds have been reported. The antibacterial activities of the synthesized compounds were primarily determined by paper disc diffusion method. The minimum inhibitory concentration (MIC) of each compound was also determined by tube dilution process. Seven different human pathogenic bacteria and eighteen different plant pathogenic bacteria were used for the antibacterial activity studies. While all synthesized compounds have shown significant antibacterial activity, one intermediate silyl compound has shown remarkably high antibacterial property. 5-substituted derivatives have shown relatively higher activity than non-substituted compounds. Polar substituent which increases hydrophilicity may have a positive impact on the antibacterial property.展开更多
Phosphine oxide-Sc(OTf)3 catalyzed regio-and enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates is described. Awide variety of optically active tertiary 5-bromo-1,3-oxazinan-2-ones can b...Phosphine oxide-Sc(OTf)3 catalyzed regio-and enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates is described. Awide variety of optically active tertiary 5-bromo-1,3-oxazinan-2-ones can be obtained with high regio-and enantioselectivity.展开更多
文摘The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane（DMNNDO） was improved by using tri（hydroxymethyl）nitromethane and acetone as starting materials through a ＂one-pot＂ method combined with alkaline hydrolysis and nitrosation reactions. The yield of DMNNDO was increased from 37% to 45%. The structure of DMNNDO was characterized by IR,^1H NMR,^13 C NMR,and elemental analysis. Also the thermal decomposition of DMNNDO was studied by using DSC and TG-DTG to find that there are primarily two exothermic decomposition processes between 90 and 300 oC. The crystal structure of DMNNDO was studied by X-ray single-crystal diffraction for the first time. The molecular structure exists as a dimeric form due to the presence of nitroso group. The crystal belongs to monoclinic system,space group C2/c with a = 14.515（3）,b = 9.955（2）,c = 11.897（2） °,β = 98.500（3）°,V = 1.6998（2） nm^3,Z = 8,D_c = 1.486 g×cm^-3,μ = 0.128 mm^-1,F（000） = 800,S = 1.055,R = 0.0358 and wR = 0.0917. In particular,DMNNDO could be easily hydrolyzed in hydrous systems and the hydrolysis mechanism in CDCl_3 was revealed by means of NMR monitoring.
文摘Eight new Schiff bases of 5-nitro and 5-bromo-substituted 1,10-phenanthroline-2,9-dicarboxaldehydes with sulfur-containing amines, thiosemicarbazide, S-alkyl/aryl dithiocarbazates and 2-mercaptoaniline have been synthesized and characterized by a variety of spectroscopic methods. The condensation reactions of the dialdehydes with the amines were carried out both in the presence and absence of conc. sulfuric acid. A significant increase in yield of the Schiff bases was observed when the reactions were carried out in the presence of sulfuric acid.
文摘Schiff bases are known to possess anticancer, antibacterial, antifungal, antitubercular, anti-inflammatory, antimicrobial and antimalarial properties. In this paper antibacterial studies against variety of plants and human pathogenic bacteria with eight newly synthesized Schiff bases and several intermediate silyl compounds have been reported. The antibacterial activities of the synthesized compounds were primarily determined by paper disc diffusion method. The minimum inhibitory concentration (MIC) of each compound was also determined by tube dilution process. Seven different human pathogenic bacteria and eighteen different plant pathogenic bacteria were used for the antibacterial activity studies. While all synthesized compounds have shown significant antibacterial activity, one intermediate silyl compound has shown remarkably high antibacterial property. 5-substituted derivatives have shown relatively higher activity than non-substituted compounds. Polar substituent which increases hydrophilicity may have a positive impact on the antibacterial property.
基金supported by the National Natural Science Foundation of China (21632005, 21172221)
文摘Phosphine oxide-Sc(OTf)3 catalyzed regio-and enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates is described. Awide variety of optically active tertiary 5-bromo-1,3-oxazinan-2-ones can be obtained with high regio-and enantioselectivity.
