Synthesis and structure of products of hydroxylamine acylation with 3-carboxy-2,2,5,5-tetramethylpyrrolinoxyl derivatives

The reaction of NH₂OH with the derivatives of 2,2,5,5-tetramethylpyrrolin-1-oxyl-3-carboxylic acid in all events led to the formation of a mixture of the corresponding nitroxylhydroxamic acid with a stable O-acylhydroxylamine. The ratio between the products depends on the nature of the acylating agent and under the studied conditions varies from ∼5.5: 1 to 1: 3 indicating the comparable nucleophilicity in this reaction of N and O atoms in the hydroxylamine. The most active chloride of the mentioned acid alongside the indicated products afforded in a considerable yield N,O-diacylhydroxylamine and the triacylated hydroxylamine, 3-{[(2,2,5,5-tetramethyl-1-oxylopyrrolin-3-yl)carbonyloxyimino][(2,2,5,5-tetramethyl-1-oxylopyrrolin-3-yl)carbonyloxy]-methyl}-2,2,5,5-tetramethylpyrrolin-1-oxyl. The structure of both latter compounds was established by XRD analysis.     

Synthesis of hydroxyisoxazolidines on the surface of adsorbents

The reaction of arylhydroxamic acids with , -unsaturated carbonyl compounds on the surface of adsorbents without a solvent leads, depending on the properties of the adsorbent, to the formation of 2-aroyl-3-hydroxyisoxazolidines and/or 2-aroyl-5-hydroxyisoxazolidines. Reactions on the surface of silica gel and di- and triethylaminoethylcellulose proceed regioselectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 976–979, July, 1990.     

Herbicidal hydroxylamine derivatives

The synthesis of 2-alkyl(dialkyl)amino-4-chloro-sym-triazine derivatives of hydroxylamine, N-methylhydroxylamine, and N-phenylhydroxylamine has been effected and their properties have been studied. The thermal and catalytic polycondensation of the 2-alkyl(dialkyl)amino-4-chloro-6-N-phenyl(methyl)hydroxyamino-sym-triazines accompanied by the liberation of hydrogen chloride and the formation of linear polycondensates with 3–4 members has been observed.For part IX see [9].     

Herbicidal hydroxylamine derivatives

2-Arylimino-3-methoxy-1,3-thiazolidin-4-ones were obtained by the reaction of N-arylthiocarbamoyl-O-methylhydroxylamines with chloroacetyl chloride. The products are isomerized to 2-methoximino-3-aryl-1,3-thiazolidin-4-ones on heating with methanol in the presence of sodium methoxide. The UV, IR, and PMR spectra were used to determine the structures of the isomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1481–1485, November, 1970.     

Herbicidal hydroxylamine derivatives

The energies of intermolecular hydrogen bonding for eight amino derivatives of sym-triazines were obtained from the temperature dependence of the equilibrium constants, which were determined by ebullioscopic and cryoscopic methods. It is shown that the investigated compounds form cyclic, centrosymmetrical dimers under the influence of hydrogen bonds. The nitrogen in the 1 or 5 position of the ring is a proton acceptor.See [1] for communication XXXIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 124–128, January, 1972.     

Herbicidal derivatives of hydroxylamine

The prototropic transformation of O-(N-methylcarbamidomethyl)-N-carboisopropoxy-N-phenylhydroxylamine in the presence of sodium ethoxide to form isopropyl phenylcarbamate, N-phenyl-N-methylurea, and glyoxylic acid derivatives was studied. A similar reaction with 2-phenyl-4-methyl-1,2,4-oxadiazine-3,5-dione is accompanied by ring contraction and the formation of 1-phenyl-3-methyl-5-hydroxyhydantoin.See [1] for communication XXXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 245–248, February, 1971.     

Synthesis and structure of 1,4,5,8-tetraethynylnaphthalene derivatives

1,4,5,8-Tetraethynylnaphthalene derivatives 4a-c were synthesized for the first time. X-ray crystallographic structure analysis of 4a revealed three different modes of distortion, expanding of the substituents, twisting of the naphthalene skeleton and bending of the acetylene units, to reduce steric repulsion.     

Synthesis and structure of some thienopyrimidine derivatives

A series of substituted thieno[2,3-d]pyrimidines was synthesized starting from ethyl-2-amino-4-isopropylthiophene-3-carboxlate. Reaction of 2-hydrazino-5-isopropyl-thieno[2,3-d]pyrimidin-4(3H)-one and its 3-methyl analogue with different reagents afforded thieno[2,3-d]triazolo[4,3-a]pyrimidines and thieno[3,2-e]triazolo[4,3-a]pyrimidines, beside open chain derivatives. Correspondence: Atef A. Hamed, Department of Chemistry, Faculty of Science, Menoufia University, Shebin El Koam, Egypt.     

Synthesis and structure of new 3,7,10-substituted-phenothiazine derivatives

The synthesis of new 3,7-dibromophenothiazine derivatives bearing bromoalkyl, mercaptoalkyl and alkylthioacetate groups on the N atom at position 10 is reported. The Suzuki coupling reaction of one of these derivatives via the bromine atoms at positions 3 and 7 with bromothiophene derivatives is also discussed.      

Synthesis and structure characterization of novel luteolin derivatives

A series of novel luteolin derivatives was synthesized employing the Vilsmeier-Haak-Arnold reaction from the intermediate compound 3′,4′,7-trichloro-5-hydroxyflavone, which was obtained from luteolin. These derivatives may be used to improve the pharmacological activities of luteolin.     

Synthesis,structure and reactivity of amino-benzodifurane derivatives

The reactivity of amino groups of some dialkyl esters of 2,6-diamino-benzo[1,2-b:4,5-b′]difuran-3,7-dicarboxylic acid towards acylic reactants was investigated. The easy and chemoselective obtainment of the N,N′-acetyl- and N,N′-benzoyl-derivatives makes the diamino compounds suitable monomers to prepare polymers with tunable chemo-physical behavior. Two novel polyamides, potentially useful for applications in the field of organic electronics, were synthesized and their properties examined. Single crystal X-ray analysis was performed on some of the prepared compounds, thus obtaining information on the extent of electronic conjugation. The obtainment of an oxazinone derivative by cyclization reaction of an N,N′-benzoyl ester was also described.     

Synthesis and structure of bifunctional N-alkylbenzimidazole phenylboronate derivatives

N-Methyl and N-n-butyl-2-(2-boronophenyl)benzimidazoles are accessed from the corresponding mono-N-alkyl-ortho-phenylenediamines, either using a polyphosphoric acid-mediated cyclisation with ortho-bromobenzoic acid, or preferably using an Oxone-mediated cyclisation of the corresponding aldehyde, followed by a lithium-exchange and borylation sequence. The resulting boronic acids show unusual physical and chemical properties, as shown by 11B NMR and X-ray crystallography.     

Spectrophotometric determination of hydroxylamine and its derivatives in pharmaceuticals

A sensitive spectrophotometric method for the determination of hydroxylamine is described. The method is based on the oxidation of hydroxylamine to nitrite using sodium arsenate under alkaline condition. The formed nitrite is determined based on the diazo coupling reaction between p-nitroaniline and N-(1-naphthyl)ethylenediamine dihydrochloride [NEDA]. The system obeys Beer's law over the concentration range 0-7 microg of hydroxylamine at 545 nm and the colour is stable for 3 h. The molar absorptivity of the colour system is found to be 6.7 x 10(4) l mol(-1) cm(-1). The relative standard deviation is 1.2% for ten determinations at 4 microg of hydroxylamine. Interferences due to various foreign ions have been studied and the method has been applied to the determination of hydroxylamine and its derivatives used in pharmaceutical formulations after hydrolysis.     

手性螺-环丙烷双内酯化合物的合成与结构

本文进一步研究了5-(l-孟氧基)-3-溴-2(5H)-呋喃酮(1)与氧的亲核试剂,如二苯甲醇、苯甲醇、α-甲基苯甲醇、薄荷醇、冰片醇发生新颖的串联不对称双Michael加成/分子内亲核取代反应,合成了一般方法难以合成的含有多个手性中心的螺[1-溴-4-l-孟氧基-5-氧杂-6-氧代双环[3.1.0]己烷-2,3'-(4'-亲核基-5'-孟氧基丁内酯)](4a-4e)。通过元素分析,IR,UV,^1HNMR,^1^3CNMR,MS,[α]~D^2^0波谱分析数据以及X四圆衍射确定了4a-4e的化学结构和绝对构型。     

Synthesis and structure of new 1,3,5-triazine-pyrazole derivatives

We have studied the reaction of methylenedicarbonyl compounds with 4,6-disubstituted 2-hydrazinyl-1,3,5-triazine in order to obtain novel coupled biheterocyclic aromatic systems with potential bioactivity. Reaction conditions were studied and optimized, and a series of 4,6-disubstituted 2-(1H-pyrazolyl)-1,3,5-triazines were obtained with good yield.     

Synthesis and structure of derivatives of azadithiapentaleneanthrone and isothiazoleanthrone

The reaction of N,N-dialkyl- or N,N-diaryl-1,5-diaminoanthrones with sulfur in a polar aprotic solvent in the presence of a base leads to the formation of 4-alkyl(aryl)amino-9-alky(aryl)-5H-anthra[1,9,8-bcde]-9-aza-1,10⁴-di-thiapentalen-5-ones. The reaction of the 1,5-diaminoanthrone, followed by methylation, leads to 7-amino-10-methylthio- and 7-amino-8,10-dimethylthio-6H-anthra[9,1-cd]isothiazol-6-ones. The structures of the last two compounds and of 4-methylamino-9-methylazadithiapentaleneanthrone were studied by x-ray crystallography. Elimination of the amino group occurs in each series. The structural features and the spectral characteristics of the new heterocyclic systems are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 417–425, March, 1990.     

Synthesis and crystal structure of two derivatives of benzodiazepines

Two benzodiazepine derivatives, C₂₃H₂₂N₂O (I), 2-methyl-8-methoxy-2,4-diphenyl-2,3-dihydro-1H-1,5-benzodiazepine, and C₂₂H₁₇N₃O₂Br₂ (II), 2-methyl-7-nitro-2,4-bis(4′-bromophenyl)-2,3-dihydro-1H-1,5-benzodiazepine, were studied by single crystal X-ray diffraction method. Compound (I) crystallizes in the monoclinic system, space group P2₁/c, a = 13.1703(17) Å, b = 11.1990(14) Å, c = 12.9093(16) Å, β = 107.831(2)°, V = 1812.6(3) ų, Z = 4. Compound (II) crystallizes in the monoclinic system, space group P2₁/n, a = 11.7345(12) Å, b = 12.7477(13) Å, c = 13.5965(14) Å, β = 95.221(2)°, V = 2025.4(4) ų, Z = 4. The molecules of (I) and (II) have T-shape form with the diazepine ring at the junction point. The seven membered central benzodiazepine ring in both structures adopt a twist-boat conformation. The crystal packing is stabilized by C-H…π (in I) and C-H…O (in II) interactions.