1006894-80-9Relevant articles and documents
Controlled release of volatile aldehydes and ketones from dynamic mixtures generated by reversible hydrazone formation
Levrand, Barbara,Fieber, Wolfgang,Lehn, Jean-Marie,Herrmann, Andreas
, p. 2281 - 2314 (2007)
Delivery systems generated by reversible hydrazone formation from hydrazine derivatives (see Fig. 1) and carbonyl compounds in H2O efficiently increase the long-lastingness of volatile aldehydes and ketones (R 1R2C=O) in various perfumery applications. The hydrazones are usually obtained in an (E) configuration at the imine double bond (NHN=C) and, in the case of aliphatic acylhydrazones R′CO-NH-N=CR 1R2 (R′ = alkyl), as syn and anti conformers with respect to the amide bond (CO-NHN). An average free-energy barrier of ca. 78kJ/mol was determined for the amide-bond rotation by variable-temperature 1H-NMR measurements (Fig. 2). In the presence of H2O, the hydrazone formation is entirely reversible, reaching an equilibrium composed of the hydrazine derivative, the carbonyl compound, and the corresponding hydrazone. Kinetic measurements carried out by UV/VIS spectroscopy showed that the same equilibrium was reached for the formation and hydrolysis of the hydrazone. Rate constants are strongly pH-dependent and increase with decreasing pH (Table 1). The influence of the hydrazine structure on the rate constants is less pronounced than the pH effect, and the presence of surfactants reduces the rate of equilibration (Tables 1 and 3). The full reversibility of the hydrazone formation allows to prepare dynamic mixtures by simple addition of a hydrazine derivative to several carbonyl compounds. Dynamic headspace analysis on dry cotton showed that the presence of a hydrazine derivative significantly increased the headspace concentrations of the different carbonyl compounds as compared to the reference sample without hydrazine (Table 4). The release of the volatiles was found to be efficient for fragrances with high vapor pressures and low H2O solubility. Furthermore, a special long-lasting effect was obtained for the release of ketones. The simplicity of generating dynamic mixtures combined with the high efficiency for the release of volatiles makes these systems particularly interesting for practical applications and will certainly influence the development of delivery systems in other areas such as the pharmaceutical or agrochemical industry.
Diarylsemicarbazones: Synthesis, antineoplastic activity and topoisomerase I inhibition assay
Asis, Silvia E.,Bruno, Ana M.,Martinez, Andrea R.,Sevilla, Maria V.,Gaozza, Carlos H.,Romano, Alejandra M.,Coussio, Jorge D.,Ciccia, Graciela
, p. 517 - 523 (1999)
A series of diarylsemicarbazones was synthesized and tested against human neoplastic cell lines. The more active members have a 1-naphthyl ring at the carbamidic nitrogen, and chloro, dimethylamino or nitro group substituents at the benzylidene moiety. None of these showed affinity to DNA. One of the more active compounds was tested as a topoisomerase I inhibitor and showed a potent effect. SAR studies demonstrated linear correlation between lypophilicity and activity on the most sensitive lines and a definite conformational shape for antineoplastic action. Copyright (C) 1999 Elsevier Science S.A.
Acid Hydrazide: A Potential Reagent for the Synthesis of Semicarbazones
Nath, Amit R.,Yehye, Wageeh A.
, p. 4301 - 4312 (2018/11/23)
Complex semicarbazone derivatives were successfully synthesized from substituted semicarbazides in acidic ethanol upon heating in the presence of aldehyde. The reaction is functional group tolerant and chemoselective because no terminal hydrazine moiety i
Microwave-assisted Synthesis and Bioevaluation of Some Semicarbazones
Jafri, Laila,Ansari, Farzana L.,Jamil, Maryam,Kalsoom, Saima,Qureishi, Sana,Mirza, Bushra
experimental part, p. 950 - 959 (2012/08/28)
In continuation to our efforts in finding potential therapeutic agents, a variety of biologically significant semicarbazones were synthesized by the reaction of different carbonyl compounds with phenyl semicarbazides through microwave irradiation. Initial
Photochromism of (E)-4-phenyl-1-(pyridine-2-ylmethylene)semicarbazide
Lin, Lirong,Fan, Weizhen,Chen, Shui,Ma, Jie,Hu, Wangxia,Lin, Yiji,Zhang, Hui,Huang, Rongbin
, p. 2562 - 2567 (2013/02/25)
A photochromism molecule, (E)-4-phenyl-1-(pyridine-2-ylmethylene) semicarbazide (1), was reported. Photochromism of 1 in solution was shown to result from the trans-cis photoisomerization of its C=N double bond, by using absorption, 1H NMR (inc
Synthesis, characterization and physiochemical information, along with antimicrobial studies of some metal complexes derived from an ON donor semicarbazone ligand
Siji,Kumar, M.R. Sudarsana,Suma,Kurup, M.R. Prathapachandra
experimental part, p. 22 - 28 (2010/06/21)
Eight new transition metal complexes of benzaldehyde-N(4)-phenylsemicarbazone have been synthesized and characterized by elemental analyses, molar conductance, electronic and infrared spectral studies. In all the complexes, the semicarbazone is coordinate
USE OF DYNAMIC MIXTURES FOR A CONTROLLED RELEASE OF FRAGRANCES
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Page/Page column 27, (2008/06/13)
The present invention relates to a delivery system in the form of a dynamic mixture obtained by reacting together, in the presence of water, at least one hydrazine derivative with at least one perfuming, flavoring, insect repellent or attractant, bactericide and/or fungicide aldehyde or ketone. The invention's mixture is capable of releasing in a controlled and prolonged manner said aldehyde or ketone in the surrounding environment. Furthermore, the present invention concerns also the use of said dynamic mixtures as perfuming ingredients as well as the perfuming compositions or perfumed articles comprising the invention's mixtures.
Structural modifications of the primary amino group of anticonvulsant aryl semicarbazones
Dimmock,Puthucode,Lo,Quail,Yang,Stables
, p. 83 - 88 (2007/10/02)
A number of aryl semicarbazones had been shown previously to possess significant anticonvulsant properties. The principal objective of the present investigation was to determine the importance of the primary amino group in this series of compounds by replacing it with other substituents. The results indicate that the amino group was not essential for anticonvulsant activity. However its replacement by an aryl ring generally abolished activity while a terminal phenylamino function was better tolerated. Thus both the size of the group and its hydrogen bonding capabilities appear to influence bioactivity. Alteration of the oxygen atom of the semicarbazones by isosteres did not enhance anticonvulsant properties.
Synthesis and Properties of 1-Benzothiopyranopyrimidine-2,4-(3H)diones (10-Thia-5-deazaflavins)
Yoneda, Fumio,Tsukuda, Kinshiro,Kawazoe, Michiko,Sone, Atsuko,Koshiro, Akira
, p. 1329 - 1334 (2007/10/02)
Treatment of 6-arylthiouracils with the Vilsmeier reagent (dimethylformamide-phosphorus oxychloride) gave the corresponding 6-arylthio-5-formyluracils, which could alternatively be prepared by the condensation of 6-chloro-5-formyluracils with thiophenols.Dehydrative cyclization of the above 5-formyluracils with polyphosphoric acid gave 1-benzothiopyranopyrimidine-2,4-(3H)diones (10-thia-5-deazaflavins).These 10-thia-5-deazaflavins oxidized alcohols to give the corresponding carbonyl compounds with the aid of strong base, and they were hydrogenated to 1,5-dihydro-10-thia-5-deazaflavins.Treatment of 10-thia-5-deazaflavins with the concentrated aqueous potassium hydroxide led to the exclusive formation of 1,5-dihydro-10-thia-5-deazaflavins and 1,5-dihydro-10-thia-5-deazaflavins-5-ones via intermolecular oxidation-reduction (disproportionation) between initially formed 1,5-dihydro-5-hydroxy-10-thia-5-deazaflavins and unchanged 10-thia-5-deazaflavins.
