- Kinetic and mechanistic study of N-aminopiperidine formation via the raschig process
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Formation of N-aminopiperidine (NAPP) in the reaction of monochloramine with piperidine was studied by varying the reagents concentrations, pH and temperature. The study was carried out in diluted solutions, recording simultaneously monochloramine concentration by UV spectrophotometry at 243 nm and hydrazine concentration at 237 nm after treatment with formaldehyde. The presence of two competitive reactions: formation of NAPP and a complex parallel reaction limiting the yield of hydrazine, was established. Reaction products were characterized by GC/MS analysis. The rate constant of NAPP formation and activation parameters were determined, k1 = 56 × 10 -3 M-1 s-1 (25°C) and k1 = 9.3 × 106 exp(-46.5/RT) M-1 s-1, respectively. Pleiades Publishing, Ltd., 2013.
- Darwich,Elkhatib,Pasquet,Delalu
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- Kinetic modelling of synthesis of N-aminopiperidine from hydroxylamine-o-sulfonique acid and piperidine
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A new route to synthesize N-aminopiperidine (NAPP) from hydroxylamine-O-sulfonique acid (HOSA) and piperidine was described. Kinetics of the reaction was investigated to optimize the conditions of the synthesis. Since the reaction is fast, this study was carried out in a diluted medium (10-3 to 10-2 mol/l). To determine the concentration of the reaction product, NAPP was allowed to react with formaldehyde and the product was analysed by UV and HPLC techniques. The formation of NAPP is consistent with the first-order reaction to two reagents, governed by the nucleophilic substitution via SN2 mechanism. Oxidation of NAPP by HOSA was identified as the main secondary reaction which consistently reduced the yield of NAPP. A number of differential equations were elaborated and solution of these equations serves to predict the behavior of the system as a function of the reagent concentrations, pH and temperature. From the corresponding mathematical treatment a unique implicit expression was derived that characterizes the reaction medium. It was found that the [PP] 0/[HOSA]0 molar ratio (p), the initial concentrations of [PP]0 and [HOSA]0, the ratio of rate constants k 2/k1 and temperature are the only parameters that affect the yield of NAPP from HOSA. The results calculated from this model are in good agreement with the experimental data and they can be used to determine the optimal conditions of the reaction. Pleiades Publishing, Ltd., 2012.
- Labarthe,Bougrine,Pasquet,Delalu
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- N-Amino-1,8-Naphthalimide is a Regenerated Protecting Group for Selective Synthesis of Mono-N-Substituted Hydrazines and Hydrazides
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A new route to synthesis of various mono-N-substituted hydrazines and hydrazides by involving in a new C?N bond formation by using N-amino-1,8-naphthalimide as a regenerated precursor was invented. Aniline and phenylhydrazines are reproduced upon reacting these individually with 1,8-naphthalic anhydride followed by hydrazinolysis. The practicality and simplicity of this C?N dihalo alkanes; developed a synthon for bond formation protocol was exemplified to various hydrazines and hydrazides. N-amino-1,8-naphthalimide is suitable synthon for transformation for selective formation of mono-substituted hydrazine and hydrazide derivatives. Those are selective mono-amidation of hydrazine with acid halides; mono-N-substituted hydrazones from aldehydes; synthesis of N-aminoazacycloalkanes from acetohydrazide scaffold and inserted to hydroxy derivatives; distinct synthesis of N,N-dibenzylhydrazines and N-benzylhydrazines from benzyl halides; synthesis of N-amino-amino acids from α-halo esters. Ecofriendly reagent N-amino-1,8-naphthalimide was regenerated with good yields by the hydrazinolysis in all procedures.
- Manoj Kumar, Mesram,Venkataramana, Parikibanda,Yadagiri Swamy, Parikibanda,Chityala, Yadaiah
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supporting information
p. 17713 - 17721
(2021/11/10)
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- Optimization of biaryloxazolidinone as promising antibacterial agents against antibiotic-susceptible and antibiotic-resistant gram-positive bacteria
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We previously discovered a series of novel biaryloxazolidinone analogues bearing a hydrazone moiety with potent antibacterial activity. However, the most potent compound OB-104 exhibited undesirable chemical and metabolic instability. Herein, novel biaryloxazolidinone analogues were designed and synthesized to improve the chemical and metabolic stability. Compounds 6a-1, 6a-3, 14a-1, 14a-3 and 14a-7 showed significant antibacterial activity against the tested Gram-positive bacteria as compared to radezolid and linezolid. Further studies indicated that most of them exhibited improved water solubility and chemical stability. Compound 14a-7 had MIC values of 0.125–0.25 μg/mL against all tested Gram-positive bacteria, and showed excellent antibacterial activity against clinical isolates of antibiotic-susceptible and antibiotic-resistant bacteria. Moreover, it was stable in human liver microsome. From a safety viewpoint, it showed non-cytotoxic activity against hepatic cell and exhibited lower inhibitory activity against human MAO-A compared to linezolid. The potent antibacterial activity and all these improved drug-likeness properties and safety profile suggested that compound 14a-7 might be a promising drug candidate for further investigation.
- Wu, Yachuang,Ding, Xiudong,Yang, Yifeng,Li, Yingxiu,Qi, Yinliang,Hu, Feng,Qin, Mingze,Liu, Yajing,Sun, Lu,Zhao, Yanfang
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- Selective reduction of N-nitroso aza-aliphatic cyclic compounds to the corresponding N-amino products using zinc dust in CO2–H2O medium
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[Figure not available: see fulltext.] A new method for reduction of N-nitroso aza-aliphatic cyclic compounds employing zinc in pressurized CO2–H2O medium has been developed. H2O and NH4Cl were used as hydrogen donors, and reduction was performed under environmentally benign conditions. The presented approach allowed to obtain the respective N-amino products selectively and in excellent yields (up to 97%).
- Yang, Weiqing,Lu, Xiang,Zhou, Tingting,Cao, Yongjing,Zhang, Yuanyuan,Ma, Menglin
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p. 780 - 783
(2018/10/20)
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- Synthesis and antibacterial activity evaluation of novel biaryloxazolidinone analogues containing a hydrazone moiety as promising antibacterial agents
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A series of linezolid analogues containing a hydrazone moiety were designed, synthesized and evaluated for their antibacterial activity. Most compounds exhibited more potent antibacterial activity against S.aureus, MRSA, MSSA, LREF and VRE pathogens as compared with linezolid and radezolid. Compounds 9a, 9c, 9f, 9g, 10m and 10t were more potent against tested clinical isolates of MRSA, MSSA, VRE and LREF as compared to linezolid. Compound 9a exhibited comparable activity with linezolid against human MAO-A for safety evaluation and showed moderate metabolism in human liver microsome. The most promising compound 9a showed remarkable antibacterial activity against S.aureus, MRSA, MSSA, LREF and VRE pathogens with MIC value of 0.0675 mg/mL, respectively, which was 15- to 30-fold more potent than linezolid.
- Wu, Yachuang,Ding, Xiudong,Ding, Liang,Zhang, Yongsheng,Cui, Lei,Sun, Lu,Li, Wei,Wang, Di,Zhao, Yanfang
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p. 247 - 258
(2018/09/18)
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- N - amino piperidine hydrochloride preparation method
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The invention relates to a preparation method of N-aminopiperidine hydrochloride. The preparation method comprises the steps: mixing piperidine with urea, and performing heating reflux reaction for 2-8 hours to obtain N-formamide piperidine; introducing chlorine gas for reaction for 1-2.5 hours when the dissolved N-formamide piperidine is at 0-20 DEG C, then carrying out Hoffmann rearrangement reaction under an alkaline condition to obtain N-aminopiperidine, reacting N-aminopiperidine with concentrated hydrochloric acid to obtain N-aminopiperidine hydrochloride. According to the preparation method of N-aminopiperidine hydrochloride, urea which serves as a raw material is low in cost and easy to obtain, highly toxic compounds such as hydrazine hydrate are not used, and nitro compounds with strong carcinogenicity are not produced in a synthetic process; and reaction conditions are mild, operation is simple, after-treatment is simple and convenient, and reaction yield is high.
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Paragraph 0030; 0031; 0032; 0033; 0034; 0035-0037
(2017/08/25)
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- Synthesis of Novel Saccharide Hydrazones
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Synthesis of important heterocyclic hydrazine derivatives N-aminopyrrolidine, N-aminopiperidine, and N-aminoazepane from hydrazine hydrate and dihalogenides were examined and optimized. These heterocyclic hydrazine derivatives were used in condensation reactions with six different monosaccharides to form corresponding hydrazones. Biological evaluations of these novel compounds, which are simple acyclic nucleoside analogs, were done. L-Arabinose N-aminoazepane hydrazone showed minor anti-HIV activity, giving a starting point for further structural modifications. (Chemical Equation Presented).
- Ilisson, Mihkel,Tomson, Kristjan,Selyutina, Anastasia,Türk, Silver,M?eorg, Uno
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supporting information
p. 1367 - 1373
(2015/06/18)
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- Novel route to the synthesis of chalcogenolanes, chalcogenanes, and 1,2-dichalcogenaepanes
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The saturated heterocyclic compounds C4H8Y, C 5H10Y, and C5H10Y2 (Y = Se or Te) have been prepared by the reaction of 1,4-dibromobutane or 1,5-dibromopentane with potassium chalcogenides. The novelty of the route consists of the use of the hydrazine hydrate-KOH system for the reductive generation of potassium selenide, telluride, diselenide or ditelluride from elemental chalcogens.
- Levanova,Grabel'Nykh,Elaev,Russavskaya,Klyba,Albanov,Korchevin
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p. 1345 - 1352
(2014/07/21)
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- Reduction of hydrazines to amines with aqueous solution of titanium(iii) trichloride
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N-N bond cleavage in hydrazines is widely used in the preparation of amines and thus occupies a significant place in organic synthesis. In this paper, we report a new method for the reductive cleavage of N-N bonds in hydrazines by commercially available and cheap aqueous titanium(iii) trichloride. The reaction proceeds smoothly under a broad pH range from acidic to neutral and basic conditions to afford amines in good yields. This method is compatible with substrates containing functionalities such as C-C double bonds, benzyl-nitrogen bonds, benzyloxy and acyl groups. The Royal Society of Chemistry 2011.
- Zhang, Yan,Tang, Qiang,Luo, Meiming
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supporting information; experimental part
p. 4977 - 4982
(2011/08/05)
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- MACROCYCLES AND THEIR USES
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The present application describes organic compounds that are useful for the treatment, prevention and/or amelioration of diseases
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- Process for the Preparation of 1-Aminopiperidine Derivatives
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The present invention relates to a process for the preparation of compounds of the general formula (I). These are used as important intermediates in the preparation of bioactive substances. Preparation is carried out starting from dicarbonyl compounds of the general formula (II), which are reacted with appropriate hydrazine derivatives of the general formula (III) and subsequently hydrogenated. The present invention also relates to advantageous intermediate compounds.
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Page/Page column 3; 5
(2009/01/20)
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- Method for the Synthesis of Exocyclic Derivatives of Cycloalkyl-Hydrazines and Exocyclic Derivatives of Heterocycloalkyl-Hydrazines
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The invention relates to a method for the synthesis of exocyclic derivatives of cycloalkyl-hydrazines and exocyclic derivatives of heterocycloalkyl-hydrazines. The invention is characterised in that the method comprises a step consisting in demixing a solution containing said synthesised derivative, by reacting a heterocyclic amine with monochloramine, in an organic phase and an aqueous phase with the addition of anhydrous sodium hydroxide. According to the invention, the starting amine which has not reacted is collected and reused directly without any additional treatment. The inventive method can also be used to obtain the corresponding exocyclic heterocycloalkyl-hydrazine or cycloalkyl-hydrazinederivative derivative at a low cost compared to that of other known methods.
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(2008/06/13)
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- METHOD FOR PREPARING N-AMINOPIPERIDINE AND ITS SALTS
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The invention concerns a novel method for preparing N-aminopiperidine of formula (I):
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Page/Page column 2
(2008/06/13)
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- SYNTHESIS OF 1-AMINOPIPERIDINE
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This invention relates to a method for synthesizing 1 -amino piperidine (N- aminopiperidine) which selects a proper molar ratio of the starting materials, preferably a cumulative mole ratio of piperidine to the aqueous hydroxylamine-O-sulfonic of at least 2: 1, and closely regulates the reaction temperature and the method of product isolation to achieve a high product conversion.
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Page/Page column 2-4
(2008/06/13)
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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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- 6-Substituted pyrido-pyrimidines
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The present invention provides compounds of the Formula I and II: wherein R1, R3, W, Z, X1, X2, Ar1, R8 and R9 are as defined herein, and methods and intermediates for their preparation and uses thereof.
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- Remedies for reperfusion injury containing integrin alphanubeta 3 antagonist
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An objective of the present invention is to provide an agent that is clinically effective in the treatment or prevention of reperfusion injury. The agent for use in the treatment or prevention of reperfusion injury according to the present invention comprises an integrin αvβ3 antagonist, a pharmaceutically acceptable salt thereof, or a solvate thereof as active ingredient.
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- Alkylamine derivatives of dihydropyridine NPY antagonists
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A series of non-peptidergic antagonists of NPY have been synthesized and are comprises of amino and piperazine derivatives of 4-phenyl-1,4-dihydropyridines of Formula 1. where X is CH or N As antagonists of NPY-induced behavior, these compounds are expected to act as effective anorexiant agents in promoting weight loss and treating eating disorders.
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- m-SUBSTITUTED BENZOIC ACID DERIVATIVES EXHIBITING INTEGRIN ALPHA-V BETA-3 ANTAGONISM
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An object of the present invention is to provide m-substituted benzoic acid derivatives having integrin αvβ3 antagonistic activity. The derivatives according to the present invention are compounds represented by formula (I) or pharmaceutically acceptable salts or solvates thereof, which are useful for the treatment or prevention of cardiovascular diseases, angiogenesis-related diseases, cerebrovascular diseases, cancers and metastasis thereof, immunological diseases, osteopathy and other diseases: wherein A represents an optionally substituted heterocyclic group containing two nitrogen atoms, a bicylic group or the like; D represents a bond, >NR4, >CR5R6, O, S, or -NR4-CR5R6-; X represents CH or N; R7 and R8 represent hydroxyl, alkyl or the like; Q represents >C=O or the like; R9 represents hydrogen, alkyl or the like; J represents a bond or alkylene; R10 represents optionally substituted hydroxyl, amino or the like; R11 represents hydrogen, alkyl or the like; m is 0 to 5; n is 0 to 4; and p and q are each 0 to 3.
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- 3-AMINOPIPERIDINE DERIVATIVES AS INTEGRIN γ(a)vγ(b)3 ANTAGONISTS
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An object of the present invention is to provide novel derivatives having integrin αvβ3 antagonistic activity wherein a basic atomic group has been attached to the 3-position of a piperidine ring either directly or through various atomic groups. The derivatives according to the present invention are compounds represented by formula (I) or pharmaceutically acceptable salts or solvates thereof, which are useful for the treatment or prevention of cardiovascular diseases, angiogenesis-related diseases, cerebrovascular diseases, cancers and metastasis thereof, immunological diseases, osteopathy and other diseases: wherein A represents an optionally substituted heterocyclic group containing at least one nitrogen atom, a bicylic group or the like; D represents a bond, >NR4, >CR5R6, O, S, or -NR4-CR5R6-; Z represents CH or N; R7 and R8 represent hydroxyl, alkyl or the like; Q represents >C=O or the like; R9 represents hydrogen, alkyl or the like; J represents a bond or alkylene; R10 represents optionally substituted hydroxyl, amino or the like; R11 represents hydrogen, alkyl or the like; m is 0 to 5; n is 0 to 4; p is 3 or 4; and q is 0 to 3.
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- MODIFIED GUANIDINO AND AMIDINO THROMBIN INHIBITORS
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Thrombin inhibitors are provided which have the formula STR1 wherein Z is a thrombin inhibitor substructure containing distal and proximal binding site residues; andR 1 is cyano, hydroxyl, alkoxy, amino, aminoalkyl or nitro.
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- CARBOXAMIDE DERIVATIVES FOR TREATING ASTHMA
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The present invention concerns novel carboxamide derivatives of formula I, set out hereinbelow which antagonize the pharmacological actions of one of the endogenous neuropeptide tachykinins at the neurokinin 2 (NK2) receptor, making them useful whenever such antagonism is desired, such as in the treatment of asthma and related conditions. The invention also provides pharmaceutical compositions containing the novel carboxamide derivatives for use in such treatment, methods for their use, and processes and intermediates for the manufacture of the novel carboxamide derivatives. STR1
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- Therapeutic heterocycles which antagonize neurokinin receptors
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Compounds of formula I STR1 wherein G, J, L, M, m and D have any of the meanings given in the specification, their N-oxides, and their pharmaceutically acceptable salts are nonpeptide antagonists of neurokinin A and useful for the treatment of asthma, etc. Also disclosed are pharmaceutical compositions, processes for preparing the compounds of formula I and intermediates.
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- Aza-enamines, VIII. - Electrophilic Substitution reactions at the Azomethine C-Atom of Aldehyde Dialkylhydrazones: Vilsmeier Formylation and Consecutive Reactions
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The reaction of hydrazones 1 with the Vilsmeier reagent yields 3-phenyl-1,4,5-triaza-1,3-pentadienium salts according to their aza-enamine character.Hydrolysis of 2 gives 1-phenylglyoxal 1-dialkylhydrazones 3, which rearrange in acidic media to 1-phenylglyoxal 2-dialkylhydrazones 4.Compound 3h forms the dihydropyrroloimidazole 5 in boiling ethanol.Pyrrolotriazinium salt 6 is obtained by the reaction of 1b with the isolated Vilsmeier reagent from dimethylformamide/oxalyl chloride.
- Brehme, Rainer
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p. 2039 - 2046
(2007/10/02)
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- Antihypertensive substituted derivatives of 2,5-diamino 1,4-diazole
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This invention relates to new chemical compounds which are derivatives of 2,5-diaminodiazoles. It relates more particularly to new 2-amino 5-(aralkylamino piperidino alkyl) diazoles. These compounds and the acid addition salts thereof have interesting therapeutical properties, particularly anti-hypertensive properties which make them useful as active ingredient of pharmaceutical compositions.
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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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- An efficient synthesis of 1,1-disubstituted hydrazines
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1,1-disubstituted hydrazines were prepared from the corresponding 1,1-disubstituted ureas by means of the Hofmann rearrangement reaction. The yields were fairly good, except from the ureas susceptible to oxidation, and thus the present method represents an additional and efficient procedure for the synthesis of 1,1-disubstituted hydrazines.
- Murakami,Yokoyama,Sasakura,Tamagawa
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p. 423 - 428
(2007/10/02)
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- Organic compounds substituted heptadeca-5,9- and 5,10-dienoic acid
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The present invention provides novel substituted heptadeca-5,9- and 5,10-dienoic acid and similar fatty acid compounds which are derivatives of certain prostaglandins and are potent thromboxane A2 inhibitors. By virtue of this pharmacological property, they represent useful pharmacological agents for a wide variety of purposes.
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- Towards a Nitrogen-fixing Cycle: Electrochemical Reduction of a Hydrazido-complex of Molybdenum(IV) under N2 to Yield the Dialkylhydrazine and a Molybdenum(0) Dinitrogen Complex
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Electrochemical reduction of trans-3CH2>)(dppe)2>+, (5) (dppe = Ph2PCH2CH2PPh2) at a Pt electrode in tetrahydrofuran-0.2 M under N2 yields the free organohydrazine and trans-, (1), under CO yields cis- and trans- and N-aminopiperidine, and under Ar yields the reduction product trans-II-(cyclo-3CH2>)(dppe)2>; the product (1) is readily converted into (5), thus a cycle for the fixation of N2 as an organohydrazine is plausible.
- Pickett, Christopher J.,Leigh, G. Jeffery
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p. 1033 - 1035
(2007/10/02)
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- Polyalkylpiperidine-spirooxazolones and their use as light stabilizers
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Compounds of the formula STR1 and their acid addition salts, wherein n is an integer from 1 to 4, R1 is hydrogen or CH3, each of R2 and R3 independently is hydrogen, C1 -C18 alkyl, C6 -C10 aryl or C7 -C9 aralkyl which is unsubsititued or substituted by chlorine or C1 -C4 alkyl, or R2 and R3 together with the carbon atom to which they are attached form a cycloalkane or alkylcycloalkane radical containing 5 to 20 carbon atoms or a polyalkylpiperidine radical, R4 is a monovalent radical as defined in claim 1, and R5 is a mono- to tetravalent radical as defined in claim 1. These compounds are valuable stabilizers for plastics. They are obtained by N-substitution of the compounds in which R4 and R5 are hydrogen.
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- Preparation of esters of phosphorus acids
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Esters of phosphorus acids are prepared by an improved process whereby aromatic alcohols and phosphorus halides are reacted at specified temperatures in the presence of amine catalysts thereby providing high yields of substantially pure esters and allowing preparation of selected halogen-containing mono- and di-esters of phosphorus acids wherein halogen is directly bonded to phosphorus having substantially no side reactant contamination. The phosphorus esters are useful as intermediates in the preparation of plasticizers, oil additives and functional fluids.
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