THE CRYSTAL STRUCTURE OF DIBROMO (PHENYL-2-PYRIDYL DIMETHYLHYDRAZONE)PALLADIUM(II)

Abstract

Nitrogen-containing heterocyclic compounds play an important role in several biological processes. Furthermore, their biological activity seems often to depend upon interaction with a metal ion. Interest in the study of hydrazones and their metal complexes has been growing because of their physiological activity, coordination capability and application in analytical chemistry.^1,2 Many hydrazones and their metallic derivatives show very interesting biological activity, e.g., as antitumour or anticonvulsant agents, and behave as cytotoxic compounds toward tumour cells.³ During the past few years, in addition to platinum compounds, coordination compounds of palladium(II) and (IV) seem to be promising in cancer chemotherapy.⁴ Due to the biological activity of heterocyclic hydrazones and in continuing our systematic investigations of the platinum group metals with hydrazones and generally with heterocyclic nitrogen donor ligands,^5–10 we report here the crystal structure of dibromo(phenyl-2-pyridyldimethylhydrazone) palladium(II).     

SYNTHESIS AND BIOLOGICAL ACTIVITY OF SOME NEW 8-HYDROXYQUINOLINE SULPHONAMIDE DERIVATIVES

Abstract

Some new derivatives containing both 8-hydroxyquinoline and sulphonylamino β-lactams and thiazolidinones have been prepared. These compounds were synthesized from the corresponding 8-hydroxyquinoline sulphonylhydrazide (1) by converting it to hydrazones (2). The latter hydrazones (2) were easily transformed to β-lactams (3) and thiazolidinones (4) by cyclocondensation reaction with chloroacetyl chloride and/or mercaptoacetic acid. Some metal chelates with Fe³⁺. Co²⁺+, Ni²⁺, Cu²⁺ and Cd²⁺ have been prepared for some of the compounds and screened in vitro for their biological activity.     

Facile Synthesis of Benzotriazines and Indoles by Ring-Scissions of α-Benzotriazol-1-yl Hydrazones

Abstract: α-(Benzotriazol-1-yl)hydrazones 2a-d and 13a-c were prepared by refluxing the corresponding α-(benzotriazol-1-yl)ketones with p-tosyl hydrazide or benzenesulfonyl hydrazide. Treatment of 2a-b with n-butyllithium in the presence of TMEDA gave benzotriazines 6a-b, while lithiation of 13a-c resulted in indole derivatives 16a-c, depending on the structure of the hydrazones.     

ONE POT SYNTHESIS OF 1-(S-TRIAZOLO[4,3-c]PYRIMIDIN- 3-YL)SUBSTITUTED POLYOLS

ABSTRACT

2-N,N-Diphenylamino-4-hydrazino-6-trifluoromethylpyrimidine (5) was reacted with some aldoses to give the corresponding hydrazones (6), which on bromine oxidation cyclized to afford 1-(s-triazolo[4,3-c]pyrimidin-3-yl)substituted polyols (7).     

SOME PHOSPHORYLATED DERIVATIVES OF 1- AND 2-ADAMANTANOLS AND 1-ADAMANTYLAMINE

Abstract

The phosphorylation of 1- and 2-adamantanols and of 1-adamantylamine with POCl₃, PSCl₃, PhOP(O)Cl₂, 4-ClC₆H₄OP(O)Cl₂, and PCl₃ is described and the conversion of the obtained phosphorochloridates into a number of derivatives such as phenylhydrazides, diamidates, hydrazides, hydrazones and azides is reported.     

Action des Hydrazines Fluoroalkylées Sur Les α-Cetophosphonates: Synthèse des Hydrazones α-Phosphonylées N-Fluoroalkylées

In the present work, we study the reaction of fluorinated hydrazines H ₂ N-NHR _F with α-ketophosphonates 1, which lead to N-fluoroalkylated α-phosphonylated hydrazones 2. The stereochemistry of the hydrazones 2 was determined by multinuclear NMR experiments ( ¹ H, ¹³ C, ¹⁹ F, and ³¹ P) and IR spectroscopy.     

Mercuric Acetate in Organic Synthesis: A Simple Procedure for the Synthesis of Pyrazolines1

Reaction of aldehyde hydrazones (1) with mercuric acetate leads to the formation of nitrile imines (2) which can react insitu with olefins to produce 1,3,5-trisubstituted 2-pyrazolines (4) in good yield.     

Synthesen von Heterocyclen, 113. Mitt.: Über Reaktionen von Ketonhydrazonen mit Malonsäurederivaten

Zusammenfassung Disubst. Hydrazone cyclischer Ketone reagieren mit monosubst. Malonsäurechloriden zu 1-Dialkylamino- bzw. Diarylamino-4-hydroxy-5,6-polymethylen-2-pyridonen (2 bis7).Malonsäure und monosubst. Malonsäuren geben mit Cyclanonhydrazonen inAc ₂O Spiro-1,3-oxazine (8 bis12). Analog verhält sich das Propiophenon-(N,N-diphenyl)-hydrazon.

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Disubstituted hydrazones of cyclic ketones react with monosubstituted malonyl chlorides to give 1-dialkylamino- or 1-diarylamino-4-hydroxy-5.6-polymethylene-pyrid-2-ones (2–7).The reaction of malonic acid and monosubstituted malonic acids with the hydrazones of cyclanones in acetic anhydride yields the spiro-1.3-oxazines (8–12). A similar reaction is observed with the N,N-diphenylhydrazone of propiophenone.

     

Mercuric Nitrate‐Mediated Deprotection of Oximes,Hydrazones, and Semicarbazones

Abstract

Mercuric nitrate in wet silica gel is found to be an excellent reagent for the regeneration of carbonyl compounds from oximes, hydrazones, and semicarbazones.     

Silica Chloride/Wet SiO2 as a Novel Heterogeneous System for Deprotection of Oximes,Hydrazones, and Semicarbazones

Abstract

Oximes, hydrazones, and semicarbazones can be converted to their corresponding carbonyl compounds in good to high yields by a combination of silica chloride and wet SiO₂.     

Cp*Co(III) catalyzed annulation of N-Cbz hydrazones for the redox-neutral synthesis of isoquinolines via C–H/N–N bond activation

Abstract

A new cascade oxidative cyclization reaction of N-Cbz hydrazones with internal alkynes has been explored for the preparation of isoquinoline derivatives using Cp*Co^III-catalyst through C–H and N–N bond functionalization. N-Cbz hydrazones are rarely explored as directing group for redox-neutral [4?+?2] cyclization reaction through the cyclometallation and this catalyst system does not require any external oxidizing agent, as well as, silver or antimony salt. The current efficient approach has been utilized for the synthesis of different isoquinoline derivatives with good regioselectivity and yields.     

PTC‐Promoted Japp–Klingmann Reaction for the Synthesis of Indole Derivatives

Abstract

Indole derivatives have been efficiently synthesized from ethyl 2‐phenylhydrazono‐5‐phthalimido‐pentanoate and its derivatives, which were obtained by Japp–Klingmann reaction under phase‐transfer catalytic (PTC) conditions. Several different phase‐transfer catalysts were investigated and dimethyldioctadecyl ammonium chloride (DMDOA) was found to promote this reaction efficiently. Using DMDOA as the PTC, aryl hydrazones were obtained in yields of 90%. The pure aryl hydrazones were then efficiently cyclized to indole derivatives in yields of more than 80%.     

One-Pot Synthesis of Some New Semicarbazone,Thiosemicarbazone, and Hydrazone Derivatives of 1-Phenyl-3-Arylpyrazole-4-Carboxaldehyde from Acetophenone Phenylhydrazones Using Vilsmeier–Haack Reagent

Semicarbazone derivatives 3 of 1,3-diphenylpyrazole-4-carboxaldehyde have been synthesized in high yields through a one-pot procedure involving acetophenone phenylhydrazones 1 subjected to Vilsmeier double formylation and workup under new conditions (i.e., treatment with semicarbazide followed by sodium bicarbonate). This method is even suitable for preparing other derivatives (i.e., thiosemicarbazones 4 and hydrazones 5) in high yields.     

Protection and deprotection chemistry catalyzed by zirconium oxychloride octahydrate (ZrOCl2·8H2O)

Abstract

An efficient, chemoselective, convenient, and straightforward methodology has been developed for the protection of C=O group of aldehydes/ketones as C=N moiety of hydrazones catalyzed by ZrOCl₂·8H₂O (10 mol%) in acetonitrile and the same catalyst in methanol oxidatively cleaves C=N moiety of hydrazones to provide parent carbonyl compounds in high yields. The reactions have been performed in aerobic condition. The catalyst is inexpensive, readily available, easy to handle, insensitive to air and moisture, easily recoverable and can be reused and importantly less toxic.     

A Sensitive Analysis for Nitrosamines

Abstract

A number of nitrosamines have been reduced to hydrazines and condensed with 9-anthraldehyde and 9-phenanthraldehyde to give highly fluorescent hydrazones which can be separated by thin layer chromatography and identified using R_f, ultroviolet and mass spectra.     

Ways of Synthesis and Study of Pharmacological Activity of the Analogs and Derivatives of Medical Preparation Phosenazid

Abstract

Pnosenazid is the first representative of “day-time” tranquillizers in a set of phosphorylated carbonacid derivatives. 4-Chlor and 4-fluorphenylsubstituted analogs of phosenazid have been synthesised. On their basis phosphorylated hydrazones, semicarbazides, methylamines, oxadiazols, pyrazolidindions have been obtained.     

Hypervalent Iodine‐Mediated Synthesis of 1‐Aryl‐4‐methyl‐1,2,4‐triazolo[4,3‐a]quinoxalines by Oxidative Cyclization of Arene Carbaldehyde‐3‐methylquinoxalin‐2‐yl Hydrazones

Arene carbaldehyde‐3‐methylquinoxalin‐2‐yl hydrazones (2) obtained by the condensation of 2‐hydrazino‐3‐methylquinoxaline (1) with various aromatic aldehydes, on treatment with iodobenzene diacetate (IBD) in dichloromethane, undergo oxidative cyclization to exclusively afford 1‐aryl‐4‐methyl‐1,2,4‐triazolo[4,3‐a]quinoxalines (5) in excellent yield.     

Synthesis of 7‐Alkoxy/Hydroxy‐α‐methyltryptamines

Abstract

A simple method for the preparation of 7‐alkoxy/hydroxy‐α‐methyl‐DL‐tryptamines is reported. The key steps of the synthesis are the Japp–Klingemann coupling of 2‐piperidone‐3‐carboxylic acid 3 with diazonium salts 4, the Fischer‐type cyclization of hydrazones 5 to β‐carboline derivatives 6 and their hydrolysis to title compounds 8.     

Reaction of N-Nitro-benzotriazole with Nucleophiles

N-Nitro-benzotriazole 1 reacts with various C-nucleophiles 2 in tetrahydrofuran at room temperature to afford o-nitramidophenylazo-compounds 3a–f and o-nitramidophenyl hydrazones 3g–l, respectively. Reaction of 1 with sodium azide in aqueous acetonitrile gives a reactive 2-azidophenylnitramide intermediate 4 which is trapped by Cu-catalyzed 1,3-dipolar cycloadition with phenyl acetylene to afford 1-o-nitramidophenyl-4-phenyl-1,2,3-triazole 5. Reaction of 1 with trimethylsilylcyanide affords 3-amino-benzo[e][1,2,4]triazine 6.     

Synthesis and Molecular Structure Characterization of Novel 1,6-Diazahexatrienes

Novel 1,6-diazahexatrienes (1a–d) are a type of aza-conjugated hexatriene containing N,N-diamino moieties. We present the oxidative dimerization of 1,1,2-trisubstituted hydrazines as a synthetic approach to 1,6-diazahexatriene derivatives, rather than the expected pyrazine and pyridazine. The proposed mechanism for formation of 1a–d involves oxidative dimerization of 1,1,2-trisubstituted hydrazines via their hydrazones. The structures of 1a–d were characterized by ¹H NMR, ¹³C NMR, and mass spectroscopy. A detailed discussion regarding the character of the three-dimensional structure of 1 is based on x-ray crystallography.