Nitrourea Research Articles

Facile Synthesis and Biological Evaluation of Novel N-Nitro Urea Derivatives Incorporating Amino Acid Ethyl Esters

<span lang=PT-BR style=font-size:10.0pt;color:black;mso-font-kerning:0pt;mso-ansi-language: PT-BR> <span style=font-size:11.0pt;mso-fareast-font-family: times= new= roman;color:black;mso-font-kerning:0pt=>1. <span style=font-size:11.0pt;color:black; mso-font-kerning:0pt>Abstract A novel series of N - nitro urea derivatives 6a-w containing various amino acid ethyl esters <span style=font-size:10.0pt;mso-font-kerning: 0pt> were conveniently synthesized via three steps including nitration, carbamic chlorination, and aminolysis reactions. <span style=font-size:10.0pt;mso-bidi-font-style: italic>The structures of all compounds prepared have been confirmed by 1 H NMR, IR spectroscopy and elemental analyses, <span style=font-size:10.0pt;mso-font-kerning: 0pt>and a part has been identified by 13 C NMR <span style=font-size: 10.0pt;mso-bidi-font-style:italic>. The preliminary bioassay indicates that some of the target compounds possesses moderate herbicidal activity against Echinochloa crusgalli and Amaranthus albus . However, some of the title compounds presented high plant growth regulating activity against rice. <span style=font-size:11.0pt;mso-fareast-font-family: times= new= roman;mso-font-kerning:0pt=>2. <span style=font-size:11.0pt;mso-font-kerning: 0pt>Keywords: Amino Acid Ethyl Ester; Synthesis × N -Nitro Urea Derivative; Herbicidal Activity

Chemical Control of Pennesetum Purpureum Laboratory Trials

Dichloral urea, diethyl chloracetamide, nitrourea, chloralhydrate, sodium trichloroacetate, sodium borate, ammonium thiocynate, sodium arsenite, arsenic oxide-sulphuric acid mixture, sodium chlorate, maleic hydrazide and the salts containing inorganic ions Cu/sup 2+/, Co/sup 2+/, MoO/sub 4//sup 2-/ and Zn/sup 2+/ were tested in experimental plots for their phytotoxic activity on a hybrid variety of Pennesetum purpureum. Sodium borate (2500 Kg/hectare), Sodium arsenite (250 Kg/hectare) and sodium chlorate (1000 Kg/hectare) through soil and ammonium thiocyanate (100 Kg/hectare) through direct spray function as growth retardants. Arsenic oxide-sulphuric acid (100 : 300 Kg/hectare) spray kills the existing leaves. Sodium chlorate (250 Kg/hectare) spray exerts phytocidal action on young plants (3 weeks). Maleic hydrazide (50 Kg/hectare) exerts permanent growth suppressant action on older plants (height >=1 m) and kills the existing leaves of younger plants (height=<0.5 m). Copper sulphate (100 Kg/hectare) induces partial drying of existing leaves and cobalt sulphate in the same dose induces yellowing of leaves extending the period of growth beyond the season of maximum growth of the control. Ammonium molybdate and Zinc acetate in the same dose do not exert any perceptible effect.

Synthesis and Characterization of Urea Nitrate and Nitrourea

AbstractUrea nitrate (UN) has not found use as a legitimate explosive but is commonly used as an improvised explosive. The dehydration product of UN is nitrourea (NU). Visually both UN and NU are white solids that both melt around 160 °C. Other properties differ markedly as might be expected from an inorganic salt (UN) and an organic molecular compound (NU). An extensive physical characterization of NU and UN is reported. Two reported routes to the NU product are compared and a decomposition mechanism of UN proposed.

ChemInform Abstract: Metal‐Free Oxidative Coupling of Thiols to Disulfides Using Guanidinium Nitrate or Nitro Urea in the Presence of Silica Sulfuric Acid.

Efficient combination of nitro urea or guanidinium nitrate and silica sulfuric acid (SiO2OSO3H) as a new oxidizing system is able to oxidize a variety of aliphatic or aromatic thiols to the corresponding disulfides. The process reported here is operationally simple, environmentally benign and reactions have been mildly and heterogeneously performed in dichloromethane at room temperature.

ChemInform Abstract: A Mild Procedure for the Preparation of o‐Nitrophenols by Nitro Urea or Ammonium Nitrate in the Presence of Silica Sulfuric Acid (SiO2—OSO3H).

AbstractA mixture of ammonium nitrate or nitro urea and silica sulfuric acid is found to be efficient and environmentally friendly nitrating media for the preparation of o‐nitro phenols.

Metal-free oxidative coupling of thiols to disulfides using guanidinium nitrate or nitro urea in the presence of silica sulfuric acid

Efficient combination of nitro urea or guanidinium nitrate and silica sulfuric acid (SiO2OSO3H) as a new oxidizing system is able to oxidize a variety of aliphatic or aromatic thiols to the corresponding disulfides. The process reported here is operationally simple, environmentally benign and reactions have been mildly and heterogeneously performed in dichloromethane at room temperature. Environmentally benign and metal-free procedure has been presented for the versatile conversion of a wide variety of thiols to the corresponding disulfides.

A Mild Procedure for the Preparation of o-Nitrophenols by Nitro Urea or Ammonium Nitrate in the Presence of Silica Sulfuric Acid (SiO2-OSO3H)

A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto-nitro phenols in dichloromethane at room temperature.

Ammonium bromide as an effective and viable catalyst in the oxidation of sulfides using nitro urea and silica sulfuric acid

A new catalytic method for the chemoselective oxidation of sulfides to the sulfoxides has been studied. A variety of dialkyl, alkylaryl and diaryl sulfides were subjected to the oxidation reaction by a mixture of nitro urea, derived from urea nitrate, silica sulfuric acid (SiO2-OSO3H) and catalytic amounts of ammonium bromide in CH2Cl2 at room temperature.

ChemInform Abstract: Metal‐Free Oxidation of Urazole and 1,4‐Dihydropyridine Derivatives under Mild and Heterogeneous Conditions by Nitro Urea, Derived from Urea Nitrate, and Silica Sulfuric Acid.

AbstractAdvantages of the title procedure are the non‐toxic and mild conditions and the easy and clean work‐up of the products.

Metal-Free Oxidation of Urazole and 1,4-Dihydropyridine Derivatives Under Mild and Heterogeneous Conditions by Nitro Urea, Derived from Urea Nitrate, and Silica Sulfuric Acid

Advantages of the title procedure are the non-toxic and mild conditions and the easy and clean work-up of the products.

Urea nitrate and nitrourea: powerful and regioselective aromatic nitration agents

Urea nitrate (UN) and nitrourea (NU), easily prepared from urea and nitric acid, convert deactivated aromatic compounds to the corresponding nitrated derivatives with a high yield and a high regioselectivity under very mild conditions. The performance of the two reagents is quite similar indicating that NU is an intermediate in the UN nitration process.

Sensitivity difference of rat ascites hepatoma AH-13 and mouse leukemia L-1210 to nitrosourea derivatives.

The structure-activity relationship in different sensitivity of AH-13 and L-1210 to nitrosourea nad related derivatives was examined. N-Methyl-N-nitrosoureido derivatives, such as 1-methyl-1-nitrosourea (MNU) and 1, 1'-polymethylene-bis(3-substituted 3-nitrosourea), were inactive against AH-13 and slightly active against L-1210. On the contrary, 1, 1'-polymethylene-bis(3-substituted 1-nitrourea) derivatives were more active against AH-13 than against L-1210. The nitrosoureas which had bis(2-chloroethyl) group at the terminal were highly active against AH-13 and L-1210. One of denitrosated derivatives, 1, 1'-ethylene-bis[3-(2-chloroethyl)urea], was active against AH-13 alone. In addition, diisocyanates, nitrourea, ammonium carbamate, and 1-methyl-1-nitrourea, which are related to the nitrosourea compounds, were also tested for their activity against AH-13 and L-1210. Diisocyanates and nitrourea were active against AH-13 alone, while other compounds were all inactive.