2-nitroguanidine derivatives: X. Synthesis and nitration of 4-nitriminotetrahydro-1,3,5-oxadiazine and 2-nitriminohexahydro-1,3,5-triazine and their substituted derivatives

A new synthetic procedure was developed to obtain 1-hydroxymethyl-2-nitroguanidine from 2-nitroguanidine and formaldehyde without catalyst. Reactions of 2-nitroguanidine and its 1-methyl-and 1-phenylsubstituted derivatives with formaldehyde and urotropin under acid catalysis resulted in 4-nitriminotetrahydro-1,3,5-oxadiazine and 2-nitriminohexahydro-1,3,5-triazine and their methyl-and phenyl-substituted derivatives, whose nitration with concn. HNO₃ in the presence of acetic anhydride and concn. H₂SO₄ depending on the temperature conditions led to the formation of 4-nitrimino-3,5-dinitrotetrahydro-1,3,5-oxadiazine, 3-methyl-4-nitrimino-5-nitrotetrahydro-1,3,5-oxadiazine, 2-nitrimino-5-nitrohexahydro-1,3,5-triazine, and 1,3,5-trinitro-hexahydro-1,3,5-triazine-2-one.     

Crystal and molecular structure of 1-phenyl-2-nitroguanidine

The molecular structure of 1-phenyl-2-nitroguanidine is nonplanar, but contains two almost planar fragments: nitroguanyl and phenyl groups. Unlike previously studied nitroguanidines, in 1-phenyl-2-nitroguanidine, the nitro group is turned to the secondary amino group. However, the structural parameters of the nitroguanyl group are little different from those of nitroguanidine and its alkyl derivatives. In the benzene ring, the symmetry in the geometric parameters is not observed, which is explained by the intermolecular interaction with the neighboring molecule.     

The geometry of the nitroguanyl fragment in the simplest nitroguanidine derivatives in the absence of intermolecular interactions: The gas electron diffraction data on 1,1,3,3-tetramethyl-2-nitroguanidine

The structures and force fields of the equilibrium forms of 2-nitroguanidine (1), 1,1,3,3-tetramethyl-2-nitroguanidine (2), and nitroguanyl azide (3) were determined in the MP2(full)/6-311G(3df, 2p) approximation; wagging-inversion motions of the N amine atoms were studied. The internal rotation potential function of the NO₂ group was calculated for 1. Similar functions for 1 and 2 were also obtained in the MP2(full)/6-311G(d, p) approximation. Direct one-dimensional problems for a nonrigid model were solved by the variational method, and the distribution of torsional levels was obtained. In the region of potential minimum, rotation in both molecules had the character of large-amplitude motions. For the first time, electron diffractions data were obtained at 100°C for molecule 2 without noticeable traces of substance decomposition. A structural r _e analysis was performed using the model of large-amplitude motions for characteristic NO₂ group torsional vibrations. Vibrational corrections to internuclear distances and mean amplitudes were calculated taking into account nonlinear kinematic effects using the force fields obtained in this work. The geometry of molecule 2 calculated in the MP2(full)/6-311G(3df, 2p) approximation well corresponds to the gas electron diffraction data. The parameters of molecule 2 in the crystalline phase, however, differ substantially from the parameters of the free molecule. This corresponds with the suggestion of the influence of intermolecular H-bonds involving the imine nitrogen atom and nitro groups oxygen atoms.     

Mannich-Type Reaction for Synthesis of 3-Methyl-4-nitroimino-tetrahydro-1,3,5-oxadiazine

The reaction of N-methyl-N′-nitroguanidine with 3-methyl-4-nitroimino-tetrahydro-1,3,5-oxadiazine is a Mannich-type reaction. The reaction was catalyzed by several organic and inorganic bases at different reaction times and temperatures. Three inorganic base catalysts [potassium carbonate (K₂CO₃), sodium hydrogen carbonate (NaHCO₃), and sodium hydroxide (NaOH)] and several organic bases (methylamine, ethamine, iso-propylamine, and n-butylamine) have been studied. The results showed that both the inorganic and organic base catalysts can be used as catalysts, with the organic bases performing better. N-Methyl-N′-nitroguanidine reacts to give the title compound 2 and is catalyzed by both acids and bases. The intensity of inorganic base catalysts, reaction temperature, and reaction time had significant effects on the products.     

Theoretical studies of the structure of nitrimines. I. Structure of 2-nitroguanidine and its alkyl derivatives

The molecular structure of 2-nitroguanidine and its 1-methyl, 1-ethyl, and 1,1,3,3-tetramethyl derivatives was studied by quantum-chemical methods. The results were compared with X-ray data. Using a basis larger than 6-31G and polarization functions and including electron correlation in calculations did not improve agreement with experiment. The major reason for this is the considerable effect of the crystal field on the geometrical parameters of the molecules.     

Reactions of 1-amino-2-nitroguanidine with 2-aryl(hetaryl)-1-nitro-1-ethoxycarbonyl(benzoyl)ethenes

Reactions of 1-amino-2-nitroguanidine with 2-aryl(hetaryl)-1-nitro-1-ethoxycarbonyl(benzoyl)-ethenes proceed via initial formation the aza-Michael product, are accompanied by liberation of nitroacetic ester (or nitroacetophenone), and result in N-aryl(hetaryl)methylidene-N-(2-nitroguanidino)amines.     

Synthesis of New Nitroamino-Containing 1,2,4-Triazines by Reaction of 1-Amino-2-nitroguanidine with α-Diketones

The reaction of 1-amino-2-nitroguanidine with α-diketones (butane-2,3-dione and 1,2-diphenylethanedione) produced new specimens of nitroamino-containing 1,2,4-triazines. The structure of the synthesized compounds of linear and heterocyclic series was confirmed by ¹H, ¹³C{¹H} NMR, IR, and UV spectra.     

N-Nitroimines: I. Synthesis,Structure, and Properties of 3,5-Diamino-1-nitroamidino-1,2,4-triazole

The reaction of 3,5-diamino-1,2,4-triazole with 2-methyl-1-nitroisothiourea gives 3,5-diamino-1-nitroamidino-1,2,4-triazole instead of the expected 1-[5(3)-amino-1,2,4-triazol-3(5)-yl]-2-nitroguanidine. Almost planar structure of the molecule of 3,5-diamino-1-nitroamidino-1,2,4-triazole gives rise for direct polar conjugation which is responsible for the low basicity of the amino groups.     

An efficient and facile synthesis of novel substituted pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine

One-pot, multicomponent reaction for the synthesis of novel substituted pyrimidine derivatives: 4-amino-5-carbonitrile-2-nitroaminopyrimidine from aromatic aldehydes, 1-nitroguanidine, and malononitrile under ethanol is described. Because of containing many active functional groups, such as amino, cyan and nitro, these products are important intermediate of organic synthesis. The advantages of this procedure include the short reaction time, mild reaction conditions, and excellent yields.     

β-nitro- and β-bromo-β-nitrostyrenes in the reactions with aminonitroguanidine

The conditions for the reactions of ??-nitro- and ??-bromo-??-nitrostyrenes with 1-amino-2-nitroguanidine resulting in the amination products, 1-nitro- and 1-bromo-1-nitro-2-aryl-2-(2-nitroguanidinoamino) ethanes, were found. Under the action of the basic catalysts or prolonged boiling, the adducts derived from the gem-bromonitrostyrenes undergo decomposition to form N-arylmethylidene-N-(2-nitroguanidino)amines.     

Vibrational spectra of 1,1,3,3-tetramethyl-2-nitroguanidine and their interpretation with the use of scaling of quantum-chemical force field

The IR (4000–50 cm⁻¹) and Raman (3500–170 cm⁻¹) spectra of solid 1,1,3,3-tetramethyl-2-nitroguanidine (TMNG) were obtained. The spectra were interpreted using the scaling of the TMNG quantum-chemical force field in the B3LYP/6-311G(d,p) approximation. Transferable scale factors necessary for the interpretation of spectra of more complex related compounds were determined. The scaled harmonic force field is supposed to be used in the analysis of the available gas-phase electron diffraction data for TMNG. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 495–498, March, 2008.     

New representatives of nitroamine-containing 1,2,4-triazoles: Synthesis and structure

The interaction of 1-methyl-1-nitroso-2-nitroguanidine with carboxylic acid hydrazides results in formation of N-(2-nitroguanidino)amides that easily give 3(5)-nitroamino-5(3)-alkyl(aryl)-1,2,4-triazoles under refluxing in aqueous alkaline medium. We have developed a one-pot method to prepare such heterocyclic structures; the synthesis of one of the sample compound has given an example of the method applicability. The compounds structures have been confirmed by UV, IR, ¹H, and ¹³C-{¹H} NMR spectroscopy.     

2-Nitroguanidine derivatives: XI. Reactions of <Emphasis Type="Italic">N</Emphasis>′-nitrohydrazinecarboximidamide and 2-methylidene-<Emphasis Type="Italic">N</Emphasis>′-nitrohydrazinecarboximidamide with glyoxal

The reaction of glyoxal with N′-nitrohydrazinecarboximidamide (1-amino-2-nitroguanidine) in the presence of sodium hydroxide at a molar ratio of 1 : 1 : 1 gave N′-nitro-2-(2-oxoethylidene)hydrazinecarboximidamide as a mixture of syn and anti isomers, whereas at a reactant ratio of 1:2:2 N′-nitro-2-[(5-nitroamino-2H-1,2,4-triazol-3-yl)methyl]hydrazinecarboximidamide and 3-nitroamino-4,5-dihydro-1,2,4-triazin-5-ol were formed. N′-Nitro-2-(2-oxoethylidene)hydrazinecarboximidamide reacted with N′-nitrohydrazinecarboximidamide in boiling ethanol to give N′-nitro-2-[(5-nitroamino-2H-1,2,4-triazol-3-yl)methyl]hydrazinecarboximidamide, while in glacial acetic acid 2,2′-(ethane-1,2-diylidene)bis(N′-nitrohydrazinecarboximidamide) was obtained. The latter was also formed in the reaction of glyoxal with N′-nitrohydrazinecarboximidamide in acetic acid at room temperature. The reaction of 2-methylidene-N′-nitrohydrazinecarboximidamide with glyoxal led to the formation of 3-nitroimino-2,3,4-5-tetrahydro-1,2,4-triazine-5-carbaldehyde or 1-(methylideneamino)-2-(nitroimino)imidazolidine-4,5-diol, depending on the conditions.     

2-Nitroguanidine Derivatives: VI. Synthesis and Chemical Properties of Hydrazo- and Azobis(nitroformamidine)

New methods have been proposed for the synthesis of hydrazobis(nitroformamidine), and its reactions with electrophilic reagents, formaldehyde and glyoxal, have been studied. Oxidation of hydrazobis-(nitroformamidine) with atmospheric oxygen in glacial acetic acid in the presence of a catalytic amount of N2O4 gives crystalline azobis(nitroformamidine). Ionization constants of the oxidation product, determined by potentiometric titration (pKa ¹ = 3.50, pKa ² = 7.93), indicate considerable increase in the NH acidity as compared to 2-nitroguanidine. Reactions of azobis(nitroformamidine) with -dicarbonyl compounds lead to formation of 1-diacylmethyl-N' ¹,N' ²-dinitrohydrazine-1,2-dicarboximidamides.     

Synthesis and Some Properties of 1,2-Dinitroguanidine

1,2-Dinitroguanidine is a product of nitroguanidine nitration with nitric acid and its mixtures with sulfuric acid and oleum. It is a diacid (pK _a 1.11, 11.5) and at the same time a weak base undergoing protonation at the nitrogen of the amino group (pK _BH+ -5.81). The decomposition kinetics of 1,2-dinitroguanidine was studied by spectrophotometric method both in acid and alkaline media, and the mechanism of the process was assumed. In the media of high acidity (H_o > -8) the 1,2-dinitroguanidine suffers reversible denitration into nitroguanidine. At lower acidity its conjugate acid or molecular form undergoes hydrolysis yielding nitrourea. Monoanion of 1,2-dinitroguanidine in a weak acid or in an alkali is hydrolyzed into N,N'-dinitrourea. The reaction of 1,2-dinitroguanidine with alkali in alcohol provides its salts, with nitrogen-containing bases form both salts and derivatives of 2-nitroguanidine. The treatment of 1,2-dinitroguanidine with haloalkanes results in its N-alkylated products.     

2-Nitroguanidine Derivatives: IX. Reaction of 1-Amino-2-nitroguanidine with Oxalic Acid as a Method of Synthesis of 3(5)-Nitroamino-1,2,4-triazole-5(3)-carboxylic Acid and 5,5′-Bi(3-nitroamino-1,2,4-triazole) Salts

A new procedure for the synthesis of 5(3)-nitroamino-1,2,4-triazole-3(5)-carboxylic acid and 5,5′ -bi(3-nitroamino-1,2,4-triazole) potassium salt has been developed. It includes cyclization of [2-(N²-nitro-carbamimidoyl) hydrazino]oxoacetic acid and 2,2′-bis(N ²-itrocarbamimidoyl)oxalohydrazide, respectively, which are prepared by reaction of 1-amino-2-nitroguanidine with oxalic acid. The reaction of 5(3)-nitroamino-1,2,4-triazole-3(5)-carbohydrazide with 1-methyl-2-nitro-1-nitrosoguanidine leads to N′ -(N ²-nitrocarbamimidoyl)-5(3)-nitroamino-1,2,4-triazole-3(5)-carbohydrazide whose intramolecular cyclization in the presence of bases may be regarded as a new method of synthesis of 5,5′-bi(3-nitroamino-1,2,4-triazole) salts.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 447–450.Original Russian Text Copyright © 2005 by Metelkina, Novikova, Berdonosova, Berdonosov.For communication VIII, see [1].     

Cyclization of thiosemicarbazide derivative: As a source of novel synthesis of some azoles and azines

In our study, we aimed to synthesize novel, some biologically active compounds, Azoles and Azines derivatives, that to be nitrogen-containing heterocycles, and have their diverse therapeutic values. Thiosemicarbazide, 2 , was obtained from the attack of nitrogen of hydrazine to the carbon of heteroallene function of compound 1. Triazolotriazole derivative, 4 , was obtained from the reaction of 2 with diethyl malonate. Cyclization of thiourea unit of compound 2 with heteroallene, 1 , gave trazine, 6 . Benzolyation of 2 using benzoyl chloride formed triazole derivative, 8 . Reaction of 2 and maleic anhydride gave furothiadazine, 10. Cyclohexanopyrimidinthione, 12 , was obtained from cyclocondensation of cyclohexanone with 2. Triazole, 14 , was obtained from 2 and ammonium isothiocynate under thermal condition. Reaction of 2 with ethyl bromoacetate gave thiazole derivative, 16. [2+3] Cyclocondensation of acetyl acetone with 2 provided pyrazole, 18 . Triazolotriazole, 20 , was obtained from formalin and 2. Compound 2 suffers intramolecular base mediated cyclization affording pyrazole, 21. Keeping 2 and propinaldehyde under reflux provided triazolotriazole, 24. Acylation of 2 by succinic acid formed pyridazine derivative, 27.     

Flourination of halogeno alcohols with 1,1,2,3,3,3-hexafluoropropyl diethylamine

Fluorination of halogeno alcohols with 1,1,2,3,3,3-hexafluoropropyl diethylamine (PPDA) was investigated. 2-Bromo-l-fluorobutane was obtained from the reaction of PPDA and 2-bromo-l-butanol (yield 50 %). Similar results were obtained from other aliphatic and aromatic halogeno alcohols. However, the corresponding 2,3,3,3-tetra-fluoropropionate esters were obtained from the reactions of PPDA and α-halogeno cycloalkanols, such as 2-chlorocyclohexanol.     

Characterization of oxides obtained by heating a mixture of peroxoniobic acid and peroxotitanic acid

Nb-doped TiO(2) particles were prepared by heating a mixture of peroxotitanic acid and peroxoniobic acid in air. When the heating temperature was more than 1173 K, the dominant phase obtained was rutile TiO(2), along with a small amount of TiNb(2)O(7). The relationship between the lattice parameters of the obtained rutile TiO(2) depended on the molar fraction of Nb/(Ti + Nb). In the case where peroxo compounds were used as a precursor, a change in the lattice parameters of the rutile TiO(2) was observed within the lower X(Nb) range, as compared to the alkoxide method. The results indicate that a homogeneous dispersion of doped Nb(5+) ions in the obtained rutile TiO(2) lattice was achieved by using peroxo compounds. Furthermore, the oxide particles obtained by using peroxo compounds had a lower activation energy of the carrier electrons (E(a)) and oxygen vacancies, even though the heating procedure was carried out in air. The UV-vis absorption spectra and Raman spectra of the obtained oxide particles indicated that the dominant reaction of the decomposition of O(2)(2-) ions in the TiO(2) lattice was O(2)(2-)→ O(2) + 2e(-) as a reducing agent.     

Synthesis of enantiomerically pure C2-branched-2-deoxy-heptitols

2,3; 4,5-Di-O-isopropylidene-al- -(+)-arabinose 1a reacts with di-l-menthylmalonate to give the hepturonates 2a and 3a in a manno-glaco 7.8:2.2 ratio. The C-2 branched 2-Deoxy-2-hydroxy-methyl- -manno-heptitol 6 and 2-Deoxy-2-hydroxy-methyl- -gluco-heptitol 7 were obtained by submitting 2a and 3a to routine procedures. When the same reaction was performed with di-d-menthylmalonate a 3.5:6.5 mixture of 2b and 3b was obtained. A 8.2:1.8 anti-diastereosetectivity was also observed by reacting 2,3,4,5-O-tetraacetyl-al- -(−)-arabinose 1b with di-d-menthylmalonate. The absolute stereochemistry of the major hepturonate 10 obtained in this reaction was secured by a single crystal X-ray analysis.