- POLAROGRAPHIC AND VOLTAMMETRIC DETERMINATION OF 1-(2'-NITROPHENYL)-3,3-DIMETHYLTRIAZENE
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The polarographic behaviour of 1-(2'-nitrophenyl)-3,3-dimethyltriazene in a mixed aqueos-methanolic solvent was investigated by tast polarography, differential pulse polarography, and fast scan differential pulse voltammetry at a hanging mercury drop electrode.A mechanism is suggested for the reduction of the compound investigated.The optimum conditions were found for the determination of this analyte by tast polarography over the concentration region of 100 to 2 μmol l-1 and by differential pulse polarography or fast scan differential pulse voltammetry at a hanging mercury drop electrode over the region of 100 to 0.2 μmol l-1.Additional sensitivity increase in the last-mentioned technique was achieved by adsorptive accumulation of analyte on the ahnging mercury drop surfase, owing to which the concentration region was depressed to 0.1 - 0.02 μmol l-1.
- Barek, Jiri,Drevinkova, Dana,Zima, Jiri
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- Catalytic Proton Coupled Electron Transfer from Metal Hydrides to Titanocene Amides, Hydrazides and Imides: Determination of Thermodynamic Parameters Relevant to Nitrogen Fixation
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The hydrogenolysis of titanium-nitrogen bonds in a series of bis(cyclopentadienyl) titanium amides, hydrazides and imides by proton coupled electron transfer (PCET) is described. Twelve different N-H bond dissociation free energies (BDFEs) among the various nitrogen-containing ligands were measured or calculated, and effects of metal oxidation state and N-ligand substituent were determined. Two metal hydride complexes, (η5-C5Me5)(py-Ph)Rh-H (py-Ph = 2-pyridylphenyl, [Rh]-H) and (η5-C5R5)(CO)3Cr-H ([Cr]R-H, R= H, Me) were evaluated for formal H atom transfer reactivity and were selected due to their relatively weak M-H bond strengths yet ability to activate and cleave molecular hydrogen. Despite comparable M-H BDFEs, disparate reactivity between the two compounds was observed and was traced to the vastly different acidities of the M-H bonds and overall redox potentials of the molecules. With [Rh]-H, catalytic syntheses of ammonia, silylamine and N,N-dimethylhydrazine have been accomplished from the corresponding titanium(IV) complex using H2 as the stoichiometric H atom source. The data presented in this study provides the thermochemical foundation for the synthesis of NH3 by proton coupled electron transfer at a well-defined transition metal center.
- Pappas, Iraklis,Chirik, Paul J.
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- Preparation method of PI3K inhibitor
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The invention provides a preparation method of a PI3K inhibitor. The PI3K inhibitor is (S)-2-[1-(9H-purine-6-ylamino) ethyl]-3-(dimethylamino)-5-fluoroquinazoline-4 (3H)-ketone, and the structural formula of the PI3K inhibitor is shown in the specification. The method comprises three steps of reactions. The method has the advantages of simple reaction steps, mild reaction conditions, indiscriminate application of the solvent, economy and environmental protection. The PI3K inhibitor is subjected to optical purification and salifying crystallization refining through organic acid resolution and has simplicity in operation, improved yield, low cost and more stable batch-to-batch quality in comparison with present silica gel column chromatography and preparation separation and is suitable for industrial production.
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Paragraph 0062; 0065-0066
(2020/08/02)
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- Ammonia-dimethylchloramine system: Kinetic approach in an aqueous medium and comparison with the mechanism involving liquid ammonia
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After an exhaustive study of the system ammonia-dimethylchloramine in liquid ammonia, it was interesting to compare the reactivity of this system in liquid ammonia with the same system in an aqueous medium. Dimethylchloramine prepared in a pure state undergoes dehydrohalogenation in an alkaline medium: the principal products formed are N-methylmethanimine, 1,3,5- trimethylhexahydrotriazine, formaldehyde, and methylamine. The kinetics of this reaction was studied by UV, GC, and HPLC as a function of temperature, initial concentrations of sodium hydroxide, and chlorinated derivative. The reaction is of the second order and obeys an E2 mechanism (k1 =4.2 × 10-5 M-1 s-1, ΔH# = 82 kJ mol-1, ΔS# = -59 J mol-1 K-1) The oxidation of unsymmetrical dimethylhydrazine by dimethylchloramine involves two consecutive processes. The first step follows a first-order law with respect to haloamine and hydrazine, leading to the formation of an aminonitrene intermediate (k2 = 150 × 10-5 M-1 s -1). The second step corresponds to the conversion of aminonitrene into formaldehyde dimethylhydrazone at pH 13). This reaction follows a first-order law (k3 = 23.5 × 10-5 s-1) The dimethylchloramine-ammonia interaction corresponds to a SN2 bimoiecular mechanism (k4 = 0.9 × 10-5 M-1 s -1, pH 13, and T =25°C). The kinetic model formulated on the basis of the above reactions shows that the formation of the hydrazine in an aqueous medium comes under strong competition from the dehydrohalogenation of dimethylchloramine and the oxidation of the hydrazine formed by the original chlorinated derivative. A global model that explains the mechanisms both in an anhydrous and in an aqueous medium was elaborated.
- Stephan,Pasquet,Elkhatib,Goutelle,Delalu
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p. 340 - 351
(2008/09/21)
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- Interaction between substituted chloramines and liquid ammonia using the indirect Raschig process
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In this paper, different hydrazines are synthesised by the indirect Raschig process. This consists of introducing a substituted chloramine (R 1R2NCl) into liquid ammonia under pressure to obtain the corresponding hydrazine (R1R2NNH2). The experimental results, in disagreement with those reported in the literature, lead us to propose a new mechanistic scheme involving a chlorine transfer reaction. Thus, the formation of chloramine (NH2Cl) and the amine (R1R2NH) occurs first. Chloramine reacts immediately with the substituted amine, in agreement with the direct Raschig process, to produce the hydrazine. Under these conditions, the nature of the hydrazine is kinetically controlled by the excess amine. It is then possible to synthesise different hydrazines from the same substituted chloramine. This mechanism is validated by the following syntheses: unsymmetric dimethylhydrazine (UDMH), N-aminopiperidine (NAPP) and N-amino 3-azabicyclo[3.3.0]octane (NAZA).
- Stephan, Juliette,Berthet, Jacques,Goutelle, Veronique,Pasquet, Veronique,Delalu, Henri
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p. 808 - 812
(2007/10/03)
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- Process for the preparation of metal nitride coatings from single source precursors and precursors suitable therefor
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Metal nitride coatings are deposited effectively by the decomposition of single source metal imido-amido-amine precursors prepared by the reaction of a pentavalent metal halide with a primary amine or hydrazine. With hydrazine-derived precursors, TaN coatings may be deposited at temperatures as low as 400 degrees Celcius or lower.
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- Nodulisporic acid derivatives
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The present invention relates to novel nodulosporic acid derivatives, which are acaricidal, antiparasitic, insecticidal and anthelmintic agents.
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- POLAROGRAPHIC AND VOLTAMMETRIC DETERMINATION OF 1-(2'-CARBAMOYLPHENYL)-3,3-DIMETHYLTRIAZENE
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A study was carried out of the polarographic behaviour of the genotoxic substance 1-(2'-carbamoylphenyl)-3,3-dimethyltriazene and optimum conditions were found for its determination by tast polarography or differential pulse polarography at a static mercury drop electrode and by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 * 10-4 -2 * 10-7 mol l-1.The sensitivity of the determination can be further improved through adsorptive accumulation of the test substance on the surface of the hanging mercury drop electrode; five-minute accumulation in unstirred solution permits determination in the concentration range (2-10 * 10-8 mol l-1 and two-minute accumulation in stirred solution allows determination in the range (2-10) * 10-9) mol l-1.
- Barek, Jiri,Toubar, Safa,Zima, Jiri
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p. 2073 - 2081
(2007/10/02)
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- CYCLIC HYDROCARBONS WITH AN AMINOALKYL SIDECHAIN
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Provided are cyclic hydrocarbons of Formula I with an aminoalkyl sidechain that are useful for treating phospholipase A2 mediated conditions, diabetes, and obesity.
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- Amidrazones 13. A Convenient Method for the Preparation of 1-Alkyl-1-methylhydrazines
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An efficient one-pot procedure for the preparation of 1-alkyl-1-methylhydrazines from methylhydrazine via base-promoted hydrolysis of 1-alkyl-3-amino-4,5-dihydro-1-methyl-1H-pyrazolium halides (3) is described.
- Smith, Richard F.,Brophy, Keith A.,Rodriguez, George,Dennis, Lisa A.,Ryan, William J.
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p. 183 - 188
(2007/10/02)
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- MODELISATION GENERALE DES PROCESSUS REACTIONNELS INTERVENANT AU COURS DE LA SYNTHESE DE LA DIMETHYLHYDRAZINE ASYMETRIQUE PAR LE PROCEDE RASCHIG. QUANTIFICATION DES PRODUITS DE DEGRADATION (HYDRAZONE). I. FORMULATION DU MODELE. VALIDITE EN MILIEU DILUE. INTERPRETATION
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A kinetic model of Unsymetrical dimethylhydrazine (UDMH) formation by Raschig process has been established.Its application range runs from pH = 8 to 14.64 (4 mol.l-1 NaOH).The synthesis is controlled by the acid-base dissociation equilibria : (NH2Cl NHCl- + H+; (CH3)2NH2(+) (CH3)2NH + H+; (CH3)2NHNH2+ (CH3)2NNH2 + H+) and by the following elementary reactions : -Dimethylhydrazine elaboration molecular (NH2Cl / (CH3)2NH) and ionic (NHCl- / (CH3)2NH) processes -Dimethylchloramine formation from NH2Cl and (CH3)2NH2+ -UDMH catalytic oxidation by NH2Cl and dimethyldiazene (CH3)2N+=N- intermediate formation -Diazene decomposition to yield formaldehyde dimethylhydrazone (FDMH) -Degradation of (CH3)2N+=N- by NH2Cl -Alkaline hydrolysis of chloramine.The synthesis can be expressed by a differential system of which the integration allows to foresee the evolution of mixtures in terms of concentration, pH and temperature.In particular, it allows a numeric evaluation of FDMH, troublesome by-product of the UDMH manufacture.Significant examples selected in different pH ranges and concentration have permitted to test the coherence between experimental and calculated curves.
- Delalu, H.,Marchand, A.
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p. 2149 - 2162
(2007/10/02)
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- INFLUENCE D'UNE IONISATION DES REACTIFS SUR L'ASPECT MECANISTIQUE DE L'INTERACTION CHLORAMINE-DIMETHYLAMINE. FORMATION PARALLELE DE DIMETHYL-HYDRAZINE ET DE DIMETHYLCHLORAMINE
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The effect of acidification on the chloramine-dimethylamine reactivity has been investigated as a function of pH (13-8) and temperature (292-305 K).Kinetics results show the existence of two competitives reactions involving chloramine with neutral and ionic form of the amine.They lead respectively, according to a second order process, to the formation of dimethylhydrazine (k1 = 68. 1E-3 1. mol-1. s-1; T = 298 K) and dimethylchloramine (k2 = 210. 1E-3 1. mol-1. s-1; T = 298 K).The rate bimolecular constant calculated form the total concentration of reactives may be expressed by an equation of the from kobs = k1αΛ + k2βΑ, where αΛ and βΛ are coefficients which depend on pH and the protonation constant of dimethylamine.The enthalpy and entropy of activation for the ionic process have been determinated at 298 K.Another mechanism involving NH3Cl+ and (CH3)2NH has been discussed and a correlation between the two models established.
- Delalu, H.,Marchand, A.
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p. 1941 - 1954
(2007/10/02)
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- Characterization of a Perhydro-5,6-di(methylene)-2,4-dioxopyrimidine Intermediate and Its Cycloaddition Reactions Leading to Quinazoline Deriivatives
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Perhydro-5,6-di(methylene)-2,4-dioxopyrimidine derivative, a useful intermediate for the synthesis of some fused pyrimidines, was characterized as the cycloadduct to N-methylmaleimide.
- Noguchi, Michihiko,Doi, Kenji,Kiriki, Yasutoshi,Kajigaeshi, Shoji
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p. 2115 - 2116
(2007/10/02)
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- 3-aryl-7-chloro-3,4-dihydroacridine-1,9(2H,10H)-dione 1-oximes and 1-hydrazone derivatives, their salts, a process for their preparation, agents containing them and their use
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3-Aryl-7-chloro-3,4-dihydroacridine-1,9(2H,10H)-dione 1-oximes and 1-hydrazone derivatives of the formula I STR1 and their physiologically tolerated acid addition and ammonium salts are described, as is a process for their preparation. The new compounds are chemotherapeutic agents and are active against protozoa, especially malaria plasmodia.
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- Herbicidal sulfonylguanidine derivatives
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Selectively herbicidal compounds of the formula STR1 in which R1 is a hydrogen atom or the group STR2 R2 is a hydroxy group, a lower alkoxy group or a di-lower alkylamino group, R3 and R4 each independently is a lower alkyl group or a lower alkoxy group, X is a lower alkoxy group, a lower alkylamino group or a morpholino group, and Y is N or CH.
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- Ureas as Amine Substrates for Hydrazine and Alkylhydrazine Synthesis - Base-assisted Chlorination of Urea by Dimethylchloramine as a Route for Hydrazine and Teramethylhydrazine Synthesis
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Base-assisted chlorination of urea by dimethylchloramine is reported.It has been shown that dimethylchloramine prefers to abstract H-atom from urea, but unlike the oxidative coupling of sulphamide by chloramine via the formation of aminium radical, chlorination of urea occurs and tetramethylhydrazine forms as a result of the coupling of the dimethylamino radicals.Fairly good yields of hydrazine are obtainable in methanol, promising a feasible route for the hydrazine fuel preparation in alcohols.
- Prakash, Hari
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p. 764 - 767
(2007/10/02)
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- Reduction of Nitrosamines with Aqueous Titanium Trichloride: Convenient Preparation of Aliphatic Hydrazines
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The reduction of selected nitrosamines by aqueous TiCl3 has been investigated.In general, aliphatic nitrosamines were converted in good yield to the corresponding hydrazines, with little overreduction to the amines.Reaction proceeded rapidly at room temperature in both alkaline and acidic media.A variety of N,N-dialkylhydrazines have been isolated by using the TiCl3 method, which compares favorably with previously reported procedures for preparatively converting nitrosamines to hydrazines.In the reduction of N-nitroso-N-methylaniline, the proportion of amine in the product increased significantly as the pH of the reaction mixture was lowered, presumably reflecting the known instability of arylalkylnitrosamines in strong acid, coupled with a ready reducibility of the corresponding Fischer-Hepp intermediates; some tendency toward reductive cleavage of the N-aryl-N-alkylhydrazine's N-N-bond was also noted.Reduction of an α-nitrosamino ether gave the monoalkylhydrazine as the major product, while all other reducing agents studied converted this starting material chiefly to a mixture of primary and secondary amines.
- Lunn, George,Sansone, Eric B.,Keefer, Larry K.
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p. 3470 - 3473
(2007/10/02)
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- REACTIONS OF A DICHLOROCARBENE-RUTHENIUM COMPLEX, RuCl2(CCl2)(CO)(PPh3)2
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The dichlorocarbene ligand, in the new complex RuCl2(CCl2)(CO)(PPh3)2, readily undergoes substitution reactions in which the integrity of the metal-carbon bond is maintained.Reactions with species H2X (X=O, S, Se) give chalcocarbonyl complexes RuCl2(CX)(CO)(PPh3)2 while RXH (X=O, S) give new carbene complexes RuCl2(CO)(PPh3)2.Ammonia reacts to give a cyanide-containing complex, RuCl(CN)(CO)(NH3)(PPh3)2, and primary amines, an isocyanide complex, or in the case of certain primary diamines cyclic carbene complexes.RuCl2(CNNMe2)(CO)(PPh3)2 is formed in the reaction with N,N-dimethylhydrazine.Secondary amines, R2NH, react to give chloroaminocarbene complexes, RuCl2(CO)(PPh3)2.
- Roper, W. R.,Wright, A. H.
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p. C59 - C63
(2007/10/02)
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- CINETIQUE DE LA REACTION DE FORMATION DE LA DIMETHYLHYDRAZINE ASYMETRIQUE PAR ACTION DE LA MONOCHLORAMINE SUR LA DIMETHYLAMINE
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The kinetics of unsymetrical dimethylhydrazine (UDMH) formation from monochloramine and dimethylamine has been investigated in terms of concentration, pH (between 12 and 6 mol*l-1 of alkali hydroxyde) and temperature in the range 25-60 deg C.First order in both reagents, the reaction is independent of the concentration of alkali hydroxyde up to about pH = 12,5.At higher alkalinites, a catalysis by hydroxyde ions is observed and the rate constant is a linear function of hydroxyde ions activity.The yield of the reaction increases from pH = 12 to 13.5, on account of the dicrease of rate of dimethylhydrazine oxydation by monochloramine and beyond 14, on account of the diminution of monochloramine decomposition.
- Delalu, Henri,Marchand, Alain,Ferriol, Michel,Cohen-Adad, Roger
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p. 247 - 252
(2007/10/02)
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- Process for preparing hydrazines
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A process is disclosed for preparing anhydrous hydrazines by reacting a tertiary hydrazinium halide with a corresponding alkali metal or alkaline earth metal amide in the presence of a non-aqueous inert carrier.
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- Ureas as Amine Substrate for Hydrazine and Alkylhydrazine Synthesis---Reaction of Chloramine with Monomethylurea and Formation of 1-Methyltriazane
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Reaction of chloramine with monomethylurea has been shown to yield monomethylhydrazine and several side products, e. g., formaldehyde monomethylhydrazone, 1,1-dimethylhydrazine, methyliminotarazane, and methanol, originating from the further oxidation of monomethylhydrazine with chloramine.Evidence for the existance of 1-methyltriazane, CH3NHNHNH2, is presented for the first time.
- Prakash, Hari,Sisler, Harry H.
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p. 825 - 828
(2007/10/02)
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- The Thermolysis of Heterocyclic Aminimines
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Aminimines derived from six heterocyclic tertiary amines were thermolyzed in t-butyl alcohol at ca. 80 deg.N-Methylindoline gave a good yield of the ring-opened product, and a double elimination on 1,4,4-trimethylpiperidine gave 3,3-dimethyl-1,4-pentadiene.The aminimine derived from quinuclidine was stable to elimination under these conditions.Simple elimination products were not obtained from N-methylpyrrolidine, N-methylpiperidine, or N-methyltetrahydroisoquinoline.
- Posvic, Harvey,Meireles, Jorge C. de
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p. 1241 - 1243
(2007/10/02)
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- Novel 2,6-di-substituted phenyl-aminoquanidine containing compositions and methods of using same and pharmaceutical compositions containing the same and therapeutic method
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The invention relates to compounds of the general formula: STR1 in which one double bond is present between the carbon atom of the quanidine moiety and one of the adjacent nitrogen atoms and R0 stands for hydrogen, halogen, hydroxy, alkoxy or alkyl (1 to 6 C), R1, r2 for halogen, hydroxy, alkyl (1 to 4 C) or alkoxy (1 to 4 C), R3, r3 ', r3 " for hydrogen or alkyl (1 to 4 C), on the understanding that one of the substituents R3, R3 ' or R3 " is absent because of the presence of the double bond, R4 for hydrogen, alkyl (1-4 C), hydroxy, alkoxy (1-4 C) or amino optionally substituted with one or two alkyl (1 to 4 C) groups, R5, r6 for hydrogen, alkyl (1-6 C), acyl or R5 + R6 together represent an alkylidene, cyclic alkylidene or aralkylidene group, as well as the acid addition salts thereof, Provided that, if R4 stands for methyl and R0, R3, R3 ", R5 and R6 for hydrogen, R1 and R2 may not represent methyl simultaneously, having a strong and long-acting anti-hypertensive activity.
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- Process for preparing hydrazines
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A novel process is disclosed for preparing hydrazine, phenyl-substituted and alkyl-substituted hydrazines. The process comprises reacting an N-haloamine with the corresponding alkali metal or alkaline earth metal amide in the presence of a non-aqueous, inert carrier and at a temperature below about 0° C., briefly heating the resulting reaction mixture and separating the desired hydrazine product.
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- Novel 2,6-disubstituted phenyl-aminoguanidine compounds
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The invention relates to compounds of the general formula: EQU1 in which one double bond is present between the carbon atom of the guanidine moiety and one of the adjacent nitrogen atoms and R0 stands for hydrogen, halogen, hydroxy, alkoxy or alkyl (1 to 6 C), R1, r2 for halogen, hydroxy, alkyl (1 to 4 C) or alkoxy (1 to 4 C), R3, r3 ', r3 " for hydrogen or alkyl (1 to 4 C) on the understanding that one of the substituents R3, R3 ' or R3 " is absent because of the presence of the double bond, R4 for hydrogen, alkyl (1-4 C), hydroxy, alkoxy (1-4 C) or amino optionally substituted with one or two alkyl (1 to 4 C) groups, R5, r6 for hydrogen, alkyl (1-6 C), acyl or R5 + R6 together represent an alkylidene, cyclic alklidene or aralkylidene group, As well as the acid addition salts thereof, provided that, if R4 stands for methyl and R0, R3, R3 ", R5 and R6 for hydrogen, R1 and R2 may not represent methyl simultaneously, having a strong and long-acting anti-hypertensive activity.
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- Process for preparing N,N-disubstituted acid hydrazides
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A process for preparing N',N'-disubstituted acid hydrazides by reacting N'-monosubstituted acid hydrazides with aldehydes in the presence of hydrogen and a hydrogenation catalyst is disclosed.
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