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A so far structurally unknown polymorph (form II) of dihydrogenhydrazinium (hydrazine) sulfate(IV) was isolated as macroscopic single crystals and its structure was determined and refined as twin from single-crystal X-ray data collected at 173 K [cell parameters: a = 5.5592(11) A, b = 7.3571(15) A, c = 10.270(2) A, β = 96.75(3)°, V = 416.21(15) A3, space group P21/c]. The structure shows some similarities to the structure of the known form I: Both form II and I share zigzag shaped strands of [SO4]2– ions running along the a axes. Within both forms the strands are separated by trans type (staggered) [N2H6]2+ ions. The spatial orientation is, however, different in both forms. Consequently, distinct hydrogen bond networks are formed. The new form II was proven to be metastable and converts into form I within one day as monitored with powder X-ray diffraction (PXRD).

Background: Contact dermatitis resulting from the use of shin pads is usually caused by rubber components, dyes, benzoyl peroxide, or formaldehyde resins. Objectives: To investigate and identify a new allergen in shin pads that was responsible for severe contact dermatitis in a young football player. Methods: High-performance liquid chromatography (HPLC) of samples of shin pads was performed. The boy was patch tested with pieces of shin pads and with acetophenone azine, a chemical substance identified by HPLC in the foam of the shin pads. Results: HPLC identified acetophenone azine at concentrations of approximately 20μg/g of shin pad samples. Patch tests gave strongly positive reactions to pieces of shin pads and to acetophenone azine down to 0.001% in acetone, whereas acetophenone and hydrazine sulfate were both negative. Twenty controls were negative for acetophenone azine 0.01% in acetone. Conclusions: Acetophenone azine is a new, strong allergen of shin pads, and more generally of other sport equipment based on ethylene vinyl acetate. It may be used as a biocide, but this has to be confirmed. Further investigations are needed to understand factors such as exposure, cross-reaction patterns, metabolism, and the optimal patch test preparation. (Less)

In support of a program to develop a treatment for diseases resulting from an imbalance in dopamine levels, two drug candidates, 1 and 2, were prepared in stable isotope and C-14 labeled forms. Both compounds contained an aminothiazole ring, and the C-14 label was introduced into the ring using KS14CN. However, the use of KS14CN to form [14C]-2 gave poor results; therefore, benzoyl [14C]isothiocyanate was used instead, which led to a much improved yield. The stable isotope labeled forms were prepared with the label in the side chain from [2H5]ethyl iodide for [2H5]-1 and from 1-[13C]methyl [15N2]pyrazole[13C]carboxaldehyde, which was prepared in turn from [carbonyl-13C]DMF, [15N2]hydrazine sulfate, and [13C]methyliodide for [13C2, 15N2]-2. Copyright © 2012 John Wiley & Sons, Ltd.

Sulfonated poly(4,4′-diphenylether-1,3,4-oxadiazole) (POD) composites have been successfully prepared through solution polycondensation of 4,4′-diphenylether dicarboxylic acid and hydrazine sulfate. The reactions were performed in the presence of various types of pristine carbon nanotubes, i.e. single-, double- and multi-walled carbon nanotubes, using mild poly(phosphoric acid) as a condensing agent. The POD composites with high molecular weight (of the order of 105 g mol−1) were highly soluble in polar aprotic solvents and thermally stable at temperatures as high as 475 °C. The synthesis method used guaranteed an improved interaction between filler and matrix, thus allowing an enhanced load transfer. The overall performance of the composites was enhanced due to a synergistic reinforcement effect. The nanocomposites exhibited an increase of +33% in storage modulus, +56% in tensile strength and +245% in tensile energy to break. Copyright © 2010 Society of Chemical Industry

PBI-LiHzS composite membranes were prepared by casting N,N'-DMAc solutions containing PBI and LiHzS, where the LiHzS contents in the membranes were between 2.5 and 10 wt.-%. LiHzS was obtained by reacting hydrazine sulfate and lithium carbonate in water. PBI-LiHzS composite membranes were thermally stable up to approximately 300 °C and their acid-absorbing capabilities were comparable to those of the pure PBI membranes. The proton conductivity of PBI-LiHzS composite membranes (2.12 × 10 -2 S · cm -1 at 180 °C and 0% RH) was higher than that of pure PBI membranes when used at the same acid doping levels. The mechanical stability of the composite membranes having less than 5 wt.-% of LiHzS was found to be close to that of pure PBI membranes.

[14C]Azodicarbonamide, a potent inhibitor of HIV-1 and HIV-2 was prepared by reaction of hydrazine sulfate with potassium [14C]cyanate, followed by oxidation of the resulting biurea. The overall radiochemical yield was 57% and the specific activity of the product was 1.48 GBq/mmol (39.9 mCi/mmol). Copyright © 1999 John Wiley & Sons, Ltd.

2-Aryl-4-methoxy-9-oxocyclohepta[b]pyrylium perchlorates 1a-c reacted with hydroxylamine hydrochloride and hydrazine sulfate in the presence of triethylamine to afford 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-oximes 3a-c and 4-hydrazones 4a-c in good yields, respectively. On the other hand, the reactions with methylhydrazine and phenylhydrazine gave respectively 1-methyl- and 1-phenyl-substituted 5-aryl-3-(3-tropolonyl)pyrazoles 5a-c and 6a-c in excellent yields. Treatment with 4-nitrophenylhydrazine gave 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-(4-nitrophenyl)hydrazones 7a-c in good yields.

An improved spectrophotometric method for phosphorus determination in oils is proposed. The proposed new method has made significant improvements in safety, sensitivity, and efficiency in comparison with the current American Oil Chemists’ Society (AOCS) Official Method (Ca 12–55, corrected 1992). The AOCS method employs hydrazine sulfate as the reducing agent to generate molybdenum blue. Hydrazine sulfate is a known carcinogen in laboratory animals and a suspected human carcinogen. The chemical also irritates skin and mucous membranes. In the improved method ascorbic acid is used as the reducing agent. Ascorbic acid is equally effective as hydrazine sulfate for the color reaction. The improved method is approximately 75 times more sensitive than the AOCS method. The sensitivity is improved by measuring absorbance at the absorption peak, 825 nm, and reducing the final volume of reaction mixture for color reaction. The AOCS method determines phosphorus by measuring absorbance at 650 nm, which is about 40% of that at the absorption peak. The efficiency of this improved method is also significantly increased by reducing sample size and the volumes of sample preparation. Therefore, the improved method is more cost-effective than the AOCS method because less chemical reagents and smaller glassware are used, and the hazardous chemical waste disposal cost is eliminated. The improved method also avoids concentrated HCl and 50% KOH for sample preparation.

Poly(p-phenylen-1,3,4-oxadiazol) entsteht aus Terephthalsaure und Hydrazinsulfat in Oleum und kann aus Schwefelsaurelosung durch Nasspinnen zu Faserstoffen mit hervorragender Temperaturbestandigkeit und guten textilphysikalischen Eigenschaften verformt werden. Da das Polymere weder schmilzt noch in ulichen organischen Losungsmitteln loslich ist, steht bisher kein okonomisch und okologisch gunstiges Verarbeitungsverfahren zur Verfugung. Ziel der vorliegenden Untersuchungen war die Synthese schmelzspinnfahiger Copolyoxadiazole durch chemische Modifizierung. Dazu wurden Dicarbonsauren als Comonomere eingesetzt, die die Beweglichkeit der Polymerketten erhohen und die zwischenmolekulare Wechselwirkung beeinflussen. Die Cokondensation mit hinreichend stabilen Dicarbonsauren erfolgte in Oleum order in einem Gemisch aus Amidosulfonsaure und Schwefelsaure. Vollig ohne Schwefelsaure entstehen Copolyoxadiazole aus Dihydraziden und Dichloriden auf dem Weg uber die Polyhydrazide. Von den synthetisierten Copolyoxadizolen erwiesen sich solche als erweichungs- und schmelzfahig, die neben Terephthalsaure noch Isophthalsaure und ein oder zwei weitere Dicarbonsauren enthalten. Gute Ergebnisse wurden mit 5-Carboxypentyl-N-trimellitimid und anderen Dicarbonsauren cyclischer Imide mit aliphatischen Segmenten erzielt. Eine zusatzliche Senkung der Erweichungs- und Schmelztemperatur gelang durch geringe Anteile an aliphatischen Dicarbonsauren. Mit Bromterephthalsaure entstanden schmelzfahige Copolymere ohne aliphatische Kettensegmente. Die Erweichungs- und Schmelztemperaturen lagen zwischen 220 und 375°C. Die TG-Analyse zeigte einen nur geringen Abfall der Thermostabilitat im Vergleich zum Homopolymeren. Ausgewahlte Copolyoxadiazole wurden in einer Kolbenspinneinrichtung verarbeitet. Die Faden waren zum Teil sprode, andere flexibel und reckfahig. Poly(p-phenylene-1,3,4-oxadiazole) is prepared from terephthalic acid and hydrazine sulfate in oleum and can be formed to fibers with extraordinary temperature resistance and good textile physical properties by wet-spinning from sulfuric acid solution. Since the polymer is neither meltable nor dilutable in usual organic solvents, no efficient and ecological processing method is accessible. The aim of the present investigations was the synthesis of meltable copoly(oxadiazole)s by chemical modification for melt-spinning. Dicarboxylic acids were used as comonomers increasing the flexibility of polymer chains and influencing intermolecular interactions. The cocondensation with sufficiently stable dicarboxylic acids was carried out in oleum or in a mixture of amidosulfonic acid and sulfuric acid. Excluding sulfuric acid at all, copolyoxadiazoles were prepared with dihydrazides and dichlorides via polyhydrazides. Among the synthesized copoly(oxadiazole)s only such ones were softable and meltable, that contain isophthalic acid in addition to terephthalic acid and one or two additional dicarboxylic acids. Promising results were achieved with 5-carboxypentyl-N-trimellitic imide and other dicarboxylic acids of cyclic imides with aliphatic segments. An additional lowering of softening and melting temperature succeeded with low portions of aliphatic dicarboxylic acids. Meltable copolymers without aliphatic chain segments were obtained with bromoterephthalic acid. Softening and melting temperatures were in a range of 220–375°C. TG analysis showed only a trivial decrease of thermostability compared to the homopolymer. Selected copoly(oxadiazole)s were processed in a piston spinning machine. One part of the obtained filaments was brittle, but others were flexibel and stretchable.

2-Aryl-4-methoxy-9-oxocyclohepta[b]pyrylium perchlorates 1a-c reacted with hydroxylamine hydrochloride and hydrazine sulfate in the presence of triethylamine to afford 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-oximes 3a-c and 4-hydrazones 4a-c in good yields, respectively. On the other hand, the reactions with methylhydrazine and phenylhydrazine gave respectively 1-methyl- and 1-phenyl-substituted 5-aryl-3-(3-tropolonyl)pyrazoles 5a-c and 6a-c in excellent yields. Treatment with 4-nitrophenylhydrazine gave 2-aryl-4,9-dihydrocyclohepta[b]pyran-4,9-dione 4-(4-nitrophenyl)hydrazones 7a-c in good yields.

In an extremely fast method the reaction of hydrazine sulfate with a number of aldehydes and ketones, is accelerated by microwave irradiation under solvent free conditions in the presence of CH3CO2...

Introduction Chondroitin and dermatan sulfate (CS/DS) show considerable species, tissue, age and pathology-related structural heterogeneity. In addition within chains their sulfation patterns are not random. To elucidate their structure/function relationships, methods for complete characterization are required. A method for keratan sulfate (KS) fingerprinting (Whitham et al. 1999) has been extended for the linkage, repeat and chain cap regions of CS/DS, including the acquisition of CS/DS ratios. Methods Chains were depolymerized by 1 U/100 mg of chondroitin ABC endolyase or ACII lyase at 50 mg/ml in 0.1 m ammonium acetate, pH 8 and for 15 h at 37 °C. Alternatively, chains were de-N-acetylated by hydrazinolysis at 98 °C for 24 h at 10 mg/1 ml in anhydrous hydrazine with 100 mg/ml hydrazine sulfate. Then, they were depolymerized by 3.9 m sodium nitrite/0.28 m acetic acid at 0 °C for 4 h. Unreduced chains were released from their protein core in 0.5 m LiOH at 4 °C for 12 h. Materials were fluorescently labelled with 2-AA as previously described (Whitham et al. 1999) and characterized by HPAEC using a Dionex AS4-SC column at 50 °C and 2 ml/min with constant 15% 1 m NaOH. A 5-min isocratic period of 85% H2O/0% 2 m NaCl was followed by a linear gradient of 0–30% 2 m NaCl over 60 min. The oligosaccharides were monitored using a λex of 315 nm and a λem of 400 nm. Results and discussion This method resolves repeat region di-, tri- and tetrasaccharides, capping oligosaccharides and linkage regions and can be used to profile known and unknown oligosaccharides. Unsulfated oligosaccharides elute between 2 and 10 min, monosulfated between 7 and 30 min, disulfated between 25 and 40 min and trisulfated between 49 and 54 min. Allied with data on size, oligosaccharide identification is facilitated. Hydrazinolysis/nitrous acid depolymerization of CS/DS chains results in disaccharides from CS with 4- or 6-sulfation and from DS with 4-sulfation which retain IdoA and GlcA structures and which can be distinguished chromatographically. The methodology was used to examine CS/DS from shark, whale, bovine and human tracheal, articular and meniscal cartilage and cornea. Tracheal cartilages show predominantly 4-sulfation with porcine sources being more highly 4-sulfated (ca. 75%) than bovine (ca. 65%). Articular cartilage comprises mainly 6-sulfated GalNAc (ca. 95% in the adult), while adult meniscal cartilage shows only ca. 85%. Tracheal and articular cartilage aggrecan showed no IdoA; however, it represented ca. 20% of the uronic acids of bovine meniscal aggrecan, showing the presence of DS. Corneal CS/DS has a very low level of 6-sulfation (

Poly(1,3,4-oxadiazole-2,5-diyl-1,2-ethendiyl) and poly(1,4-phenylene-1,3,4-oxadiazole-2,5 diyl-1,2-ethenediyl) have been prepared by condensation polymerization using fuming sulfuric acid and different quantities of terephthalic acid (T), fumaric acid (F), and hydrazine sulfate (HS). Homopolymers of F and T and various copolymers of F:T have been prepared. The polymer structure was investigated by IR and visible-range spectra and elemental analysis. The existence of poly(1,3,4-oxadiazole-diylphenylene) and poly(hydrazoterephthaloyl) structures was revealed by these studies. These polymers were thermally stable, and most of them did not show a weight loss below 350°C. The relative thermal stabilities of the various polymers have been evaluated by “integral procedural decomposition temperature” and activation energy measurements.

A convenient method, not involving ashing or acid digestion, for the determination of inorganic phosphorus content in crude palm oil, is developed. Direct extraction from solvent-diluted palm oil by dilute acid allows the inorganic phosphates to be analyzed by the usual phosphomolybdenum blue complex. Using this method, phosphate analyses in palm oil samples were correlated with other oil quality parameters and the results discussed.

Two polymers built up of 1,3,4-oxadiazole-2,5-diyl and vinylene resp. ethynylene groups (polymers 2 and 3) were prepared by polycondensation of fumaramide resp. acetylenedicarboxamide with hydrazine sulfate in polyphosphoric acid. 2 and 3 exhibit the properties of conjugated polymers—dark colour, semiconductivity, and paramagnetism. The electric conductivity measurments were performed on pellets and on thin films in sandwich and surface cells. The comparison of the semiconducting properties of the polymers mutually and with poly-p-xylylidene leads to the conclusion that the trans-double bond is a better building unit for conjugated semiconductive polymers than the triple bond and the 1,3,4-oxadiazole-2,5-diyl residue is better than the 1,4-phenylene unit.

Copolymerization of para-phenylenediamine sulfate (PPD-S), hydrazine sulfate (Hy-S), and terephthalic acid (TA) in SO3 yielded solutions of poly[p-(disulfonatophenylene)terephthalamide]–co-poly(p-phenylene-1,3,4-oxadiazole) (SPT-co-POx). Reaction of PPD-S, TA, and 4,4′-sulfonyldibenzoic acid (SDBA) in SO3 gave sulfonated copolyamide (SPT-co-SPSDB) solutions. Solutions of both SPT-co-POx (mole % ratios of 70:30 to 90:10) and SPT-co-SPSDB (75:25 to 90:10) were anisotropic, illustrating liquid crystalline behavior for polymeric structures containing significant amounts of noncoaxial backbone components.

Maleic anhydride-1- and 2-13C were synthesized respectively from the available aspartic acid-4- and -3-13C by way of the corresponding bromosuccinic acids and their anhydrides. The maleic anhydrides were converted into 1,2-dihydro-3,6-pyrida-zinedione-3- and -4-13C on treatment with aqueous hydrazine sulfate. Nitrogen-15 labeled 1,2-dihydro-3,6-pyridazinedione was obtained from the latter reaction using hydrazine-15N sulfate.

Poly(1,3,4-oxadiazole-2,5-diylvinylene) and poly(1,4-phenylene-1,3,4-oxadiazole-2,5-diylvinylene) were prepared by polymerizing different quantities of terephthalic acid (T), maleic acid (M), and hydrazine sulfate (HS) in the presence of fuming sulfuric acid. Homopolymers of M and T and various copolymers of M:T were prepared. The polymers were characterized by viscosity, IR, UV, and elemental analysis. Their solubility in different solvents was investigated. The relative thermal stability of the polymers was evaluated by TGA and DTA.

The condensation product 3a of hydrazine sulfate, formaldehyde, and hydrogen peroxide, for which the tricyclic 7:6:7-ring structure 3a was previously established for the solid state by X-ray analysis, exists as a mixture of conformations 3a and 3b in solution. AM1 calculations show the two 7:6:7-tricyclic conformers 3a and 3b to be of approximately equal energy, and substantially lower in energy than the three isomeric 6:6:6-perhydroheteroanthracene conformers 2a, 2b and 2c. By contrast, analogous MNDO calculations predicted that the perhydroanthracene analog conformers 2, should be more stable than 3 [ΔHf(2) < ΔHf(3)]. AM1 calculations of model compounds, containing various subunits of the tricyclic systems, demonstrate that three significant factors are responsible for the relative energies: a) The 1,3-lone pair repulsions in the 6:6:7 system. b) The ring strain of the central tetra-aza unit in the 7:6:7 system. c) The advantageous energetic consequences of the anomeric effect in the stable conformation of the 7:6:7 system. Experimenteller Test der Strukturvorhersagen semiempirischer Methoden: Bis(1,2-dioxa-4,6-diazacycloheptano) [4′,5′,6′: 1,6,5]-[4″,5″,6″: 2,3,4]-1,2,4,5-tetraazacyclohexan; Ein 7:6:7-tricyclisches System, das von der AM1-Methode korrekt als stabiler als sein 6:6:6-tricyclisches Isomer beschrieben wird Das aus Hydrazinsulfat, Formaldehyd und Wasserstoffperoxid entstehende tricyclische Kondensationsprodukt 3a, dessen 7:6:7-Struktur bereits fruher durch Rontgenstrukturanalyse bestimmt wurde, liegt laut NMR-spektroskopischen Untersuchungen in Losung als Konformerengemisch aus 3a und 3b vor. Aus AM1- Rechnungen ergibt sich, das die beiden 7:6:7-Strukturen 3a und 3b nahezu energiegleich und stabiler sind als die 6:6:6-Isomeren 2a, 2b und 2c. MNDO sagt die umgekehrte Stabilitat voraus [ΔHf(2) < ΔHf(3)]. Durch AM1-Berechnungen von Modellverbindungen, die in den tricyclischen Systemen als Untereinheiten enthalten sind, wird gezeigt, das fur die relativen Energieunterschiede drei wesentliche Einflusse verantwortlich sind: a) Die 1,3-Wechselwirkung nichtbindender Elektronenpaare in den 6:6:6-Systemen,b) die Ringspannung der zentralen Tetraazacyclohexan-Einheit der 7:6:7-Systeme und c) die gunstigen sterischen Voraussetzungen zur konformativen Stabilisierung des 7:6:7-Systems durch den anomeren Effekt.

A mutagenesis assay employing the frog, Rana pipiens, is currently under development [McKinnell et al, 1979]. A question that must be answered is whether the frog is metabolically capable of activating a large number of promutagens. The Ames assay offers a simple means of comparing the metabolism of mutagens by different animal species. The Ames response obtained with frog-liver S-9 was compared to the response with rat-liver S-9, using the following compounds: Benzo(a)pyrene, 7,12-dimethylbenz(a)anthracene, 2-amino-fluorene, azobenzene, Sudan II, dibutylnitrosamine, hydrazine sulfate, hydroxyethylhydrazine, cyclophosphamide, 1,2-dichloroethane, tris(2,3 dibromopropyl)phosphate, diallate, quinoline, quercetin, aflatoxin B 1, emodin, and safrole. Of these compounds, activation by rat S-9 was observed for all except hydrazine sulfate and safrole. All except Sudan II, 1,2-dichloroethane, quinoline, and safrole gave positive Ames responses with frog S-9. In general, the responses with frog S-9 were quantitatively lower than those obtained with Aroclor-induced rat S-9; however, the optimum procedure for frog-liver induction has not been determined. The response to dichloroethane is very sensitive to the amount of activating enzyme present; it might be positive with optimally induced frog S-9. Thus, only two of the 15 compounds positive with rat S-9 were definitely missed when tested with frog S-9. We feel that the frog assay appears to be promising from the standpoint of false-negatives.

A convenient method for the synthesis of poly(1,3,4-oxadiazole)s of high molecular weights has been developed. These polymers were prepared readily by the direct polycondensation of dicarboxylic acids with hydrazine sulfate (1) using phosphorus pentoxide/methanesulfonic acid (PPMA) as both a condensing agent and solvent. Polycondensation of aliphatic dicarboxylic acids with 1 proceeded even at room temperature and produced poly(1,3,4-oxadiazole)s with inherent viscosities up to 1.4 dL/g. The synthesis of aromatic poly(1,3,4-oxadiazole)s from aromatic dicarboxylic acids containing phenyl ether structures was carried out by a one-pot procedure because the preactivation of dicarboxylic acids was required. The synthesis of 2,5-disubstituted-1,3,4-oxadiazoles by the reaction of carboxylic acids with 1 in PPMA was studied to demonstrate the feasibility of the reaction for polymer formation. The thermogravimetry of the aromatic poly(1,3,4-oxadiazole)s showed 10% weight loss both in air and in nitrogen at 440–490°C.

Essais avec laiton 70/30 duns des solutions de NaOH (0,2 N, 0,5 N, 1,0 N) avec addition de differents inhibiteurs. Parmiles combinaisons employees ce sont le furfural et la glucose qui sont inhibiteurs acceptables duns toutes les conditions utilisees, tandis gue les autres corps sont caracterises par le fait qu'il-y-a une inhibition maximum a des concentrations de NaOH ou d'inhibiteur definies. Ce dernier concerne p.e. rhodizonate de sodium, chromotropate de sodium et tannin. Les autres corps etudies sont: quinalizarine, 2,4-pentanedion, cyclehexanone, thiouree, dithioxamide, diethyldithiocarbamate de sodium, sulfate d'hydrazine, cupferron, cupron, gallocyanine, acriflavine et eosine. Inhibition of the corrosion of brass 70/30 in sodium hydroxide solutions Tests with brass 70/30 in NaOH (0.2 N, 0.5 N, 1.0 N) with addition of various inhibitors. Among the compounds used as inhibitors, furfural and glucose can be considered as efficient inhibitors under any test condition, while other compounds are characterized by maximum efficiencies at certain optimum concentrations of NaOH or the inhibitor respectively. This case is true e.g. with Na-rhodizonate, Na-chromotrapote and tannine. Other materials studied as inhibitors are: quinalizarine, 2,4-pentanedione, cyclohexanone, thiourea, dithiooxamide, Na-diethyldithiocarbamate, hydrazine sulfate, cupferron, cupron, gallocyanine, acriflavine and posine.

Some alicyclic poly-1,3,4-oxadiazoles were prepared from cycloalkanedicarboxylic dihydrazides or from cycloalkanedicarboxylic acids and hydrazine sulfate by solution polycondensation in polyphosphoric acid. These polymers were characterized by high melting temperature. Their preparations and physical properties, such as solubility, crystallinity and thermal stability, are described.

High molecular weight poly-N-alkylhydrazide-oxadiazoles have been prepared in poly-phosphoric acid by alkylation of poly-1,3,4-oxadiazole which was synthesized from terephthalic acid and hydrazine sulfate. Various kinds of reagents having an alkoxy group were used as alkylating agent, and N-ethylated and N-propylated polyhydrazides containing oxadiazole units were obtained. The thermal properties of the polymers obtained were investigated by using infrared spectroscopy, viscometry, differential thermometric and thermogravimetric techniques. Soluble poly-N-alkylhydrazide-oxadiazole are thermally cyclized to poly-1,3,4-oxadiazole with elimination of olefins and water at 226–330°C for propylated polydrazide and at 240–360°C for ethylated polyhydrazide. For both, weight loss in polyhydrazides occurs in two distinct stages corresponding, respectively, to cyclization and decomposition of the poly-1,3,4-oxadiazole formed in situ.

Aliphatic poly-1,3,4-oxadiazoles were prepared from aliphatic dicarboxylic dihydrazides or from dicarboxylic derivatives and hydrazine sulfate by solution polycondensation in polyphosphoric acid. Their preparation and physical properties, such as solubility, crystallinity, and thermal stability are described. Aus aliphatischen Dicarbonsaurehydraziden oder Dicarbonsaurederivaten und Hydrazinsulfat wurden durch Polykondensation in Polyphosphorsaurelosung Poly-1,3,4-oxadiazole hergestellt. Neben der Herstellung werden physikalische Eigenschaften wie Loslichkeit, Kristallinitat und Warmebestandigkeit beschrieben.

N-Methylated polyhydrazides were prepared from methylated hydrazines and terephthalic acid or dimethyl terephthalate, and from terephthalic acid, hydrazine sulfate, and dimethyl sulfate by the solution polycondensation method in fuming sulfuric acid or polyphosphoric acid.

30 Stoffe wurden als Inhibitoren der Korrosion von Messing 63/37 in Natriumhydroxid untersucht. Glucose hemmt die Korrosion vollstandig; Resorcin, Pyrogallol, Phloroglucin, Gallocyanin, Hydrazinsulfat erreichen Hemmwirkungen uber 90% in Losungen aller untersuchten NaOH-Konzentrationen. Auch Phenol, Brenzkatechin, Chinon, Pyrogallol, α-Naphthol, Chinalizarin, m-Aminophenol und Thioharnstoff erreichen noch Hemmwirkungen uber 80%. Natriumrhodizonat und Tannin sind bei hoheren Alkalikonzentrationen wirksam, Salicylaldehyd hingegen nur in 0,2 n NaOH. Acriflavin, Acetylaceton und Cupron besitzen keine ausreichende Hemmwirkung. Inhibition of the corrosion of 63/37 brass in sodium hydroxide solutions 30 substances have been investigated as inhibitors for the corrosion of 63/37 brass in sodium hydroxide solutions. Glucose retards the corrosion completely. Resorcinol, pyrogallol, phloroglucinol, gallocyanine, hydrazine sulfate, afford >90% protection to brass 63/37 in all the alkali concentrations studied. The performance of phenol, catechol, quinone, pyrogallol, α-naphthol, quinalizarin, m-aminophenol, thiourea is also satisfactory >80%. Sodium rhodizonate and tannin are effective in higher concentrations of alkali whereas salicylaldehyde is effective only in 0.2 N sodium hydroxide solution. The performance of acriflavine, acetylacetone and cupron is far from satisfactory.

Chloramine-B oxidizes amino acids such as leucine, valine, phenylalanine, alanine, glutamic acid, glutathione, and cysteine, Me2SO, hydrazine sulfate, semicarbazide hydrochloride, and cyanide and thiocyanate ions in metal salts and complexes in various solvents and buffer media. Back titrn. procedures were developed for estg. these compds. Chloramine-B stoichiometrically oxidizes amino acids in pH 5 buffer (pH 2 for cysteine), Me2SO at pH 4, hydrazine sulfate and semicarbazide hydrochloride in 2-3N H2SO4, cyanide and thiocyanates in buffers of pH 4 and 1, resp. Benzenesulfonamide, nitriles (aldehydes in the case of glutathione and cysteine), di-Me sulfone, N, and cyanates are the reaction products. The products of oxidn. are confirmed by thin-layer chromatog. and spot tests. The effect of neutral salts, H2SO4, HClO4, and HCl on the rate or stoichiometry of oxidn. was studied. [on SciFinder(R)]

The condensation product 3a of hydrazine sulfate, formaldehyde, and hydrogen peroxide, for which the tricyclic 7:6:7-ring structure 3a was previously established for the solid state by X-ray analysis, exists as a mixture of conformations 3a and 3b in solution. AM1 calculations show the two 7:6:7-tricyclic conformers 3a and 3b to be of approximately equal energy, and substantially lower in energy than the three isomeric 6:6:6-perhydroheteroanthracene conformers 2a, 2b and 2c. By contrast, analogous MNDO calculations predicted that the perhydroanthracene analog conformers 2, should be more stable than 3 [ΔHf(2) < ΔHf(3)]. AM1 calculations of model compounds, containing various subunits of the tricyclic systems, demonstrate that three significant factors are responsible for the relative energies: a) The 1,3-lone pair repulsions in the 6:6:7 system. b) The ring strain of the central tetra-aza unit in the 7:6:7 system. c) The advantageous energetic consequences of the anomeric effect in the stable conformation of the 7:6:7 system. Experimenteller Test der Strukturvorhersagen semiempirischer Methoden: Bis(1,2-dioxa-4,6-diazacycloheptano) [4′,5′,6′: 1,6,5]-[4″,5″,6″: 2,3,4]-1,2,4,5-tetraazacyclohexan; Ein 7:6:7-tricyclisches System, das von der AM1-Methode korrekt als stabiler als sein 6:6:6-tricyclisches Isomer beschrieben wird Das aus Hydrazinsulfat, Formaldehyd und Wasserstoffperoxid entstehende tricyclische Kondensationsprodukt 3a, dessen 7:6:7-Struktur bereits fruher durch Rontgenstrukturanalyse bestimmt wurde, liegt laut NMR-spektroskopischen Untersuchungen in Losung als Konformerengemisch aus 3a und 3b vor. Aus AM1- Rechnungen ergibt sich, das die beiden 7:6:7-Strukturen 3a und 3b nahezu energiegleich und stabiler sind als die 6:6:6-Isomeren 2a, 2b und 2c. MNDO sagt die umgekehrte Stabilitat voraus [ΔHf(2) < ΔHf(3)]. Durch AM1-Berechnungen von Modellverbindungen, die in den tricyclischen Systemen als Untereinheiten enthalten sind, wird gezeigt, das fur die relativen Energieunterschiede drei wesentliche Einflusse verantwortlich sind: a) Die 1,3-Wechselwirkung nichtbindender Elektronenpaare in den 6:6:6-Systemen,b) die Ringspannung der zentralen Tetraazacyclohexan-Einheit der 7:6:7-Systeme und c) die gunstigen sterischen Voraussetzungen zur konformativen Stabilisierung des 7:6:7-Systems durch den anomeren Effekt.

A study was made of the oxidation of a number of thienylbutynols to the corresponding acetylenic ketones of the thiophene series, which were converted to 3-thienylpyrazoles by treatment with hydrazine sulfate.