Showing papers on "Hydrazone published in 1984"
TL;DR: In this article, a general α-alkylation of acyclic ketones is described, which allows the overall enantioselective α-alkylation in good overall yields (44-86%,, 4 steps) and enanti-oselectivities ranging routinely from > 94% ee up to virtually complete asymmetric induction (99.5%ee).
89 citations
TL;DR: A number of hydrazines, hydrazides, and related compounds have been condensed with isatin and substituted isatins and the anticonvulsant activity of these compounds is reported.
57 citations
TL;DR: In this paper, a common metallo intermediate with a Z-structure was encountered in the oxidations of the E- and Z-pyridine 2-carbaldehyde 2pyridylhydrazone with mercuric acetate.
Abstract: Hydrazones prepared by coupling 2-acylpyridines with arylhydrazines were isolated predominantly as E-isomers when the acyl substituent R was small (H or Me). When R was a phenyl group significant yields of Z-isomers, containing an intramolecular hydrogen bond, were also isolated. Oxidation reactions of these hydrazones were not influenced by the E- or Z-geometry of the substrate contrary to earlier reports. A common metallo intermediate with a Z-structure was encountered in the oxidations of the E- and Z-pyridine 2-carbaldehyde 2-pyridylhydrazone with mercuric acetate. In oxidations of a series of hydrazones with lead tetra-acetate the product controlling factor was the nature of the methine substituent R. For ketone derivatives (R ≠ H) oxidation to fused 1,2,3-triazolium systems occurred via a 5-exo-tet cyclization with E- and Z-hydrazone substrates. For aldehyde systems (R = H) the oxidation involved dehydrogenation to a nitrilimine and gave products by solvent addition or a 5-endo-dig cyclization to fused 1,2,4-triazolo systems.
27 citations
22 citations
TL;DR: Several new uranyl(VI) complexes of some hydrazone-oximes, derived from o -chloro-, o -methyl, o -hydroxy-, p-chloro, p-methyl, p -nitro-, p -methoxybenzoylhydrazines and biacetylmonoxime, have been synthesized in absolute ethanol as mentioned in this paper.
20 citations
20 citations
TL;DR: In this paper, three potentially sexadentate phthalazine hydrazone ligands, obtained by reacting 1,4-dihydrazinophthalazine with an appropriate aldehyde, are reported, in which variable terminal donor substituents include the phenol (DPSI), N-methyl imidazole (DPIM) and pyridine (PHP) groups.
18 citations
18 citations
TL;DR: In this article, it was shown that cyclic secondary amines, when condensed with either 1 or 2, furnished only mixtures of the β-pyranosyl and β-furansyl forms, and, in some reactions, Amadori rearrangement products (2-30%).
18 citations
TL;DR: Phenylaziridine hydrazones react at 140°-160°C to provide sterically congested trisubstituted olefins in good yield.
17 citations
TL;DR: Arylazo derivatives of quinoxaline (1,4-benzodiazine, 1,4 -benzothiazine and 1, 4-bbenzoxazine) have been prepared by condensation of hydrazidoyl halides with o-phenylenediamine, o-aminothiophenol, and oaminophenol, respectively as mentioned in this paper.
TL;DR: In this article, a series of triazolotriazines were screened against the mouse M5076 reticulum cell sarcoma and P388 leukaemia in vivo but proved to have no antitumour activity.
Abstract: Interaction of 2,4-bis(dimethylamino)-6-hydrazino-1,3,5-triazine (1c) with aryl aldehydes yields a series of aryl hydrazones (4) which cyclise to 3-aryl-5,7-bis(dimethylamino)-1,2,4-triazolo[4,3-a]-[1,3,5]triazines (6) with lead(IV) acetate in dichloromethane. Rearrangement of these bicycles in methanolic sodium hydroxide affords stable isomeric 2-aryl-5,7-bis(dimethylamino)[1,2,4]triazolo-[1,5-a][1,3,5]triazines (7). Selected examples from both series of triazolotriazines were screened against the mouse M5076 reticulum cell sarcoma and P388 leukaemia in vivo but proved to have no antitumour activity.
TL;DR: The lithium salts for trityl- and diphenyl-4-pyridylmethyl-hydrazones of both aldehydes and ketones react with electrophiles (alkyl haldies, alde-hydes, and ketone) at low temperature to form C-trapped azo compounds; these intermediates decompose homolytically with loss of nitrogen below room temperature and can be diverted in a synthetically useful way to alkanes, or alkenes or alcohols.
Abstract: The lithium salts for trityl- and diphenyl-4-pyridylmethyl-hydrazones of both aldehydes and ketones react with electrophiles (alkyl haldies, aldehydes, and ketones) at low temperature to form C-trapped azo compounds; these intermediates decompose homolytically with loss of nitrogen below room temperature and can be diverted in a synthetically useful way to alkanes, or alkenes, or alcohols.
TL;DR: The 3H-Azolo-1,2,4-triazoles as mentioned in this paper were formed by cycloreactions of diazoazoles 1 with diazosalkanes 2 and with fluorene--N-, P-, S-ylides 4, respectively, (Method A) or by cyclizing dehydrogenation of diorganylmethanone (1H-azol-3-yl)hydrazones 7 (Method B).
Abstract: 3H-Azolo-1,2,4-triazole 3 entstehen durch Cycloreaktion2b) von Diazoazolen 1 mit Diazoalkanen 2 bzw. mit Fluoren-N-, P-, S-Yliden 4 (Methode A) oder durch cyclisierende Dehydrierung von Diorganylmethanon-(1H-azol-3-yl)hydrazonen 7 (Methode B). Bei beiden Methoden erfolgt die Triazolanellierung durch 1,8- bzw. 1,12-Elektrocyclisierung von Azol-3-on-(diorganylmethylen)-hydrazonen (Azine) 9, wie im Fall der 4-Nitrophenylverbindung 9dk gezeigt werden konnte. – Spektroskopische Daten (UV, 1H-NMR, 13C-NMR) der 3H-Azolo-1,2,4-triazole 3 werden diskutiert.
Reactions with Diazoazoles, VII. 3H-Azolo-1,2,4-triazoles by 1,8- or 1,12-Electrocyclizations of 3H-Pyrazol-3-one- or 3H-Indazol-3-one (Diorganylmethylene)hydrazones, Respectively
3H-Azolo-1,2,4-triazoles 3 are formed by cycloreactions 2b) of diazoazoles 1 with diazoalkanes 2 and with fluorene--N-, P-, S-ylides 4, respectively, (Method A) or by cyclizing dehydrogenation of diorganylmethanone (1H-azol-3-yl)hydrazones 7 (Method B). In both methods the anellation of the triazol system results from 1,8- or 1,12-electrocyclization of azol-3-one (diorganylmethylene)-hydrazones (azines) 9, as could be shown in the case of the 4-nitrophenyl compound 9dk. – Spectroscopic data (UV, 1H NMR, 13C NMR) of the 3H-azolo-1,2,4-triazoles 3 are discussed.
TL;DR: In this article, the relative rates of fading of azo and hydrazone tautomers were monitored by resolving the visible absorbance spectrum of the dye into two overlapping bands corresponding to each tautomer.
TL;DR: In this paper, the t-butyl-4 methyl-2 cyclohexanone (C2C) was shown to be stable in DMF a −63°C.
Abstract: On obtient la t-butyl-4 methyl-2 cyclohexanone a partir de la dimethylhydrazone correspondante sans isomerisation en la traitant par 2 equiv. d'acide m-chloroperbenzoique dans DMF a −63°C
Journal Article•
TL;DR: In this article, 16 nouvelles quinoxalyl-and isoquinolylhydrazones were described, plusieurs d'entre elles presentent de tres hautes sensibilites for le dosage spectrophotometrique des ions des metaux de transition.
Abstract: Preparation et proprietes de 16 nouvelles quinoxalyl- et isoquinolylhydrazones. Plusieurs d'entre elles presentent de tres hautes sensibilites pour le dosage spectrophotometrique des ions des metaux de transition
TL;DR: In this article, the synthesis of α-Oxo-and α-hydrazono[1. n]paracyclophanes was discussed in relation to the specific sterical structure of these diarylketones.
Abstract: Synthesis of α-Oxo- and α-Hydrazono[1. n]paracyclophanes
α-Oxo[1. n]paracyclophanes 1a – e (n = 12 – 8) were synthesized via the corresponding dithia-[1. n]paracyclophanes 5a – e and the disulfones 6a – e derived therefrom. Spectroscopic properties (IR 13C NMR) and chemical reactivity of 1a – e are discussed in relation to the specific sterical structure of these diarylketones. From 1a – e the hydrazones 2a – e were prepared as precursors of the corresponding carbenes 4.
TL;DR: In this paper, the 3-N-(p-toluenesulfonyl) derivatives of 2-acetyl and 2-benzoyl-3-aminobenzofurans have been shown to yield α-azines.
TL;DR: The reaction of equimolar amounts of saturated nitriles and azines affords hydrazone derivatives; with unsymmetrical azines the reaction is regioselective and takes place with an alkyl substituent at the end of the azines opposite to an aryl substitution as mentioned in this paper.
Abstract: Reaction of equimolar amounts of saturated nitriles and azines affords hydrazone derivatives; with unsymmetrical azines the reaction is regioselective and takes place with an alkyl substituent at the end of the azines opposite to an aryl substituent. Acid catalysed cyclisation and hydrolysis of the hydrazone derivatives yields N-unsubstituted pyrazoles, whereas aluminium chloride catalysed cyclisation of the N-ethoxycarbonyl analogues affords pyrimidones.
TL;DR: In this article, a synthesis of methylthieno[3,2-c]cyclohepteno[b]indole from 2-methylthienono[1,2]-cyclohexenone 3 is described.
TL;DR: Two types of complexes viz., adducts VOLSO4, ML2Cl2 and 2-furoylacetone hydrazone (FAH) have been synthesized and characterized on the basis of elemental analysis, electrical conductivity, molecular weight, magnetic susceptibility, electronic, ESR and IR studies as discussed by the authors.
Abstract: Two types of complexes viz., adducts VOLSO4, ML2Cl2 [M = Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II)], CuLC12.H2O and deprotonated compounds M(L-H)2(H2O)n [M = VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) n = 0 or 2], L = 2-furoylacetone hydrazone (FAH) have been synthesized and characterized on the basis of elemental analysis, electrical conductivity, molecular weight, magnetic susceptibility, electronic, ESR and IR studies. Some of these complexes have been tested for antibacterial activity against cyanobacterius TOC muscorum and found to be more active than the parent ligand.
TL;DR: In this article, the reactions of 2-diazo-1,2-diphenylethanone (1) with ketohydrazones (3a-c) in equimolecular ratio yield (diphensylacetyl)hydrazones of the corresponding benzophenones which on further treatment with 1 in equinomial ratio leads to 1-dipphenylacetyldiazomethane (1,1,3,3-tetraaryl-2-propanones (5a−c).
Abstract: The reactions of 2-diazo-1,2-diphenylethanone (1) with ketohydrazones (3a–c) in equimolecular ratio yield (diphenylacetyl)hydrazones (4a–c) of the corresponding benzophenones which on further treatment with 1 in equimolecular ratio leads to 1-diphenylacetylazo-1,1,3,3-tetraaryl-2-propanones (5a–c). The product 5a is also obtained in the reaction of 1 with benzophenone hydrazone (3a) in 2 : 1 molecular ratio. The bis(acetylacetonato)copper(II)-catalyzed reaction of 1 and also of diphenyldiazomethane (2) with ketohydrazones (3) affords ketazines (6). The mechanistic route for the formation of products is discussed.
TL;DR: In this article, the 1,3,4-oxadiazine 2, one of three known isomers formed by cycloaddition of 2,5-dimethyl-3, 4-diphenyl-cyclopentadienone and dimethyl azodicarboxylate, is isomerized by MeO−−MeOH to the hydrazone 4, the MeO of the ester group of 2 is lost and MeO is incorporated into 4 from the solvent.
Abstract: When the 1,3,4-oxadiazine 2, one of three known isomers formed by cycloaddition of 2,5-dimethyl-3,4-diphenyl-cyclopentadienone and dimethyl azodicarboxylate, is isomerized by MeO−–MeOH to the hydrazone 4, the MeO of the ester group of 2 is lost and MeO is incorporated into 4 from the solvent. In acid, e.g. trifluoroacetic acid, demethylation of 2 gives 14 in which the ester Me is lost. The hydrazone 4 also gives 14 with acid, but by a different pathway.These results were established using the structurally isomeric oxadiazines 10 and 11 as mechanistic probes; an X-ray analysis of 10 established the individual identities of these.
TL;DR: The effects of γ-irradiation on the browning reaction in the model system of fructose-phenylalanine solution were investigated in this article, where it was found that as a result of irradiation of the model systems mainly aliphatic aldehydes are formed, besides a small amount of cyclic aldehyde.
Abstract: The effects of γ-irradiation on the browning reaction in the model system of fructose-phenylalanine solution were investigated. The optical absorption recorded for irradiated and heated solutions of fructose-phenylalanine was different from those of only irradiated or only heated solutions.
To explain the role of carbonyl compounds formed during radiolysis of fructose and phenylalanine investigations of their N-methyl-benzothiazolone hydrazone hydrochloride derivatives were undertaken. It has been found that as a result of irradiation of the model system mainly aliphatic aldehydes are formed, besides a small amount of cyclic aldehydes. However during heating the contribution of aliphatic and cyclic products is similar.