Showing papers on "Hydrazone published in 1978"

Chemische synthese verzweigter polysaccharide, 5. Kopplung von oligosacchariden und amylose an verschiedene träger durch hydrazonbindung

Abstract: The coupling of glucose and maltooligomers by hydrazone linkage to carriers by means of acid hydrazide groups was investigated. The following carriers were used: (1) linear polymers such as (a) poly(ethylene glycol) with carboxymethyl (CM) end groups, (b) CM-amylose and CM-cellulose, 6-COOH amylose and 6-COOH cellulose, pectic acid, alginic acid, poly(acrylic acid); (2) multifunctional centers such as (c) CM-cyclodextrin, 1,3,5-benzenetricarboxylic acid, 1,3,4,5-benzenetetracarboxylic acid, crosslinked poly(acrylamide) (BIO-GEL). The hydrazone linkage which is formed preferably in borate buffer at pH 8,5 was stable above pH 6 and could be split by mild acid treatment at pH 4. Maltooligomeric grafts of degree of polymerization DP ≧ 4 may be extended enzymatically by phosphorolytic synthesis to amylose chains of variable length. Primer activity of the bound maltooligomers for phosphorylase was obviously not hindered by the hydrazone linkage, by free hydrazide groups, or by synthetic polymers as carriers. ABA-Block copolymers may be derived from(a), comb-like molecules from (b), and different kinds of star-like molecules from (c).

A New Synthesis of 2,3,1‐Diazaborines

Abstract: A new method for the preparation of 2,3,1-diazaborines is described. It is suggested that the observed formation of the C,B-bond by electrophilic attack with a boron halide is facilitated and o-directed by the sulfonyl hydrazone group of the educts.

Über die Eigenschaften einiger wasserlöslicher Azo‐Initiatoren

Abstract: Water soluble azo compounds of the structure 1a, b, 2a, b, 3, 4, and 5 decompose, depending on the substitution of the aromatic ring, in water already at room temperature Therefore, they are useful initiators for solution and emulsion polymerisations in this temperature region Reactions competing with thermolysis, as the formation of a hydrazone (pH>8) and ionic reactions with suitable reagents (phenols) are described

Synthesis of cationic carbonyl cyclopentadienyl complexes of molybdenum and tungsten, and X-ray crystal structure of (acetone hydrazone)-tricarbonyl(η-cyclopentadienyl)tungsten hexafluorophosphate

Abstract: Substitution of the hydrazine ligand in [Mo(η-C5H5)(CO)3(N2H4)]Cl with a range of commonly used tertiary phosphine and phosphite ligands (L) has provided a new high-yield route to [Mo(η-C5H5)(CO)3L]+ cations for the majority, but not all, of the ligands used With phosphonites, phosphinites, and smaller phosphines there is a competing reaction to give [Mo(η-C5H5)(CO)2L2]+ cations Reaction of [W(η-C5H5)(CO)3(N2H4)] Cl with PPh3and PMePh2 gives [W(η-C5H5)(CO)3L]+(L = PPh3 or PMePh2) and [W(η-C5H5)(NCO)(CO)2(PPh3)], depending on the reaction conditions The complexes [M(η-C5H5)(CO)3(N2H4)]Cl (M = Mo or W) react with acetone to give the respective hydrazone cations [M(η-C5H5)(CO)3(NH2NCMe)]+, which are thermodynamically more stable than the hydrazine precursors; [Mo(η-C5H5)(CO)3(NH2NCMe2)]+ is converted into [Mo(η-C5H5)(CO)2-(solvent)2]+ in-polar solvents at room temperature The crystal and molecular structure of [W(η-C5H5)(CO)3-(NH2NCMe2)][PF6] has been determined from three-dimensional X-ray data collected by counter methods The structure has been refined by full-matrix least-squares techniques to a final R(on F) of 0030, based on 2 141 reflections The complex crystallises in the triclinic space group P with two molecules in a cell of dimensions a= 1081 (2), b= 974(2), c= 847(2)A, α= 1133(1), β= 960(1), and γ= 951 (1)° The tungsten atom is formally seven co-ordinate and the complex is best described as possessing the ‘piano-stool’ geometry The major feature is the mode of bonding of the hydrazone ligand, which is shown to occur through the amino-nitrogen atom, in contradiction to current theories on the bonding of hydrazones to transition metals Possible factors in-fluencing the relative stability of amino- or imino-nitrogen bonding are discussed

Formation of 5-Phenyltetrazole from N2-Benzoyl-N4-(phenylsulfonyl)benzohydrazide Hydrazone

Abstract: 5-Phenyltetrazole is obtained in a moderate yield by the mercury(II) oxide oxidation of the title hydrazidine prepared from N-(phenylsulfonyl)benzohydrazonoyl chloride and benzohydrazide. The tetrazole formation is interpreted in terms of an intramolecular SN2 type process of the intermediate formazan with the removal of benzenesulfinic acid. In the absence of oxidizing agents, the hydrazidine gives 2,5-diphenyl-1,3,4-oxadiazole and 3,5-diphenyl-4-phenylsulfonylamino-4H-1,2,4-triazole.

Reaction of benzophenone hydrazone with 1-chlorobenzotriazole

Abstract: The reaction of benzophenone hydrazone with 1-chlorobenzotriazole is complex and consumes three equivalents of the oxidant. One equivalent causes oxidation to diphenyldiazomethane which reacts rapidly with a second equivalent to give benzotriazolyldiphenylmethyl chloride. This reacts slowly with further 1-chlorobenzotriazole to give chlorine and dibenzotriazol-1-yldiphenylmethane (2) and the isomeric 3-benzotriazol-1-yl-6-(benzotriazol-1-ylphenylmethylene)cyclohexa-1,4-diene (3).

Untersuchungen zur Reaktivität von Thiapseudophenalenonen und Thiapseudophenaleniumsalzen

Abstract: Das Thiapseudophenalenon I kann durch Alkylierung mit „Meerwein-Salz” in das Thiapseudophenaleniumsalz 3 uberfuhrt werden, welches mit den N-Nukleophilen N-Benzoylhydrazid und 2,4-Dinitrophenylhydrazin zu den Hydrazonen 4a sowie 4b reagiert; 1 setzt sich mit dem C-Nukleophil 5 in Acetanhydrid zu dem Thiapseudophena-fulvenderivat 6 um. 6-Oxo-6H-anthra[1,9-bc]thiophen (7) – ein anderes Thiapseudophenalenon - konnte ebenfalls mit Triathyloxoniumtetrafluoroborat in das Kation 8 uberfuhrt werden; 7 selbst reagiert mit 2,4-Dinitrophenylhydrazin zum Hydrazon 9 in Gegenwart katalytischer Mengen H3PO4. Chemical Studies about the Reactivity of Thiapseudophenalenones and Thiapseudophenalenium Salts. The thiapseudophenalenone 1 can be alkylated by „Meerwein-salt” to give the thiapseudophenalenium salt 3, which reacts with N-nucleophilic compounds (N-benzoyl- or 2,4-dinitrophenylhydrazine) to yield the hydrazones 4a and 4b. The reaction of 1 with the C-nucleophile 5 in acetic anhydride leads to the thiapseudophenafulvene derivative 6. 6H-Anthra[1,9-bc]thiophenone (7) and triethyloxonium tetrafluoroborate form the cation 8. With 2,4-dinitrophenylhydrazine in the presence of catalytic traces of H3PO4 compound 7 forms the hydrazone 9.

Mechanistic aspects of the Wolff-Kishner reaction. V. The cation effect on the reaction of benzophenone hydrazone in butyl carbitol and decyl alcohol

Abstract: The rate of the Wolff-Kishner reaction of benzophenone hydrazone in butyl carbitol increases as the cation of the alkoxide base is varied in the order K>Na>Li>Mg. The replacement of butyl carbitol by 1-decanol also accelerates the reaction, and an additional increase is caused by the presence of “crown ether”. On the basis of changes in the activation parameters, it is concluded that the reactivity of the hydrazone anion increases as the contact ion pair becomes more fully solvated and dissociated.

The hydrazinolysis of heterocyclic compounds. v: Reactions of 1-amino-4, 6-dimethylpyrimidin- 2(1h)-one hydrazone in water

Abstract: The cation of 1-amino-4, 6-dimethylpyrimidin-2(1H)-one hydrazone (1) is stable in aqueous solutions. By contrast the neutral molecule species decomposes to yield 3, 5-dimethylpyrazole (3) and 1-amino- 4, 6- dimethylpyrimidin-2(1H)-one (6) as major products, and 1, 2, 4-triazole-3, 4, 5-triamine (7) and other unidentified compounds as minor products. Covalent hydration and substituent effects in the cation species of (1) are discussed in seeking an explanation for anomalous ultraviolet spectra. Hydrogendeuterium exchange in methyl substituents is reported.

3-phenylazo-4-methyl-2,3-dihydro-1,5-benzodiazepin-2-ones

Abstract: The corresponding azo derivatives, which exist primarily in the azo form, are formed in the reaction of 2,3-dihydro-1,5-benzodiazepin-2-ones with diazonium cations. The hydrazone form of these compounds is possible in solutions of acids.

Poly(hydrazone-hydrazine)

Abstract: Disclosed is a poly(hydrazone-hydrazide) prepared from difunctional acid chlorides and 4-(hydrazonomethyl)benzoic acid hydrazide. The poly(hydrazone-hydrazide) contains repeating units corresponding to the structure: ##STR1## Films of this polymer have unobviously high tensile and tear strengths without the necessity of biaxially orienting the film.

Crystal and molecular structure of 3-phenylisoxazolin-4,5-dione-4-[3′-phenyl-(2′H)Δ3′-isoxazolin-5′-on-4′-yl]hydrazone

Abstract: The crystal and molecular structure of 3-phenylisoxazolin-4,5-dione-4-[3′-phenyl-(2′H)Δ3′-isoxazolin-5′-on-4′-yl]hydrazone, C18H12N4O4, has been determined from X-ray diffractometer data and refined by least-squares methods toR=0.047 for 1413 observed reflections. Crystals of C18H12N4O4 are monoclinic:a=13.76(1),b=11.11(1),c=14.10(1) A, β=90.5(1) °,Z=8, space groupC2/c.

Purification of 1,1-dimethyl hydrazine (UDMH) containing formaldehyde dimethyl hydrazone

Abstract: The formaldehyde hydrazone of UDMH can be removed from an aqueous solutionf UDMH by codistillation with a hydrocarbon or other solvent which is inert to both acidic or basis mediums. The solvent can then be recovered from the hydrazone solution by washing with an acid solution and the solvent can be reused.