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Hydrazines vinyl

Pyridyl)hydrazine (Aldrich), 4-acetylpyridine (Acros), N,N,N -trimethylethylenediamine (Aldrich), methylrhenium trioxide (Aldrich), InQj (Aldrich), Cu(N0j)2-3H20 (Merck), Ni(N03)2-6Il20 (Merck), Yb(OTf)3(Fluka), Sc(OTf)3 (Fluka), 2-(aminomethyl)pyridine (Acros), benzylideneacetone (Aldrich), and chalcone (Aldrich) were of the highest purity available. Borane dimethyl sulfide (2M solution in THE) was obtained from Aldrich. Methyl vinyl ketone was distilled prior to use. Cyclopentadiene was prepared from its dimer immediately before use. (R)-l-acetyl-5-isopropoxy-3-pyrrolin-2-one (4.15) has been kindly provided by Prof H. Hiemstra (University of Amsterdam). [Pg.119]

NOTE - Petrochemical plants also generate significant amounts of solid wastes and sludges, some of which may be considered hazardous because of the presence of toxic organics and heavy metals. Spent caustic and other hazardous wastes may be generated in significant quantities examples are distillation residues associated with units handling acetaldehyde, acetonitrile, benzyl chloride, carbon tetrachloride, cumene, phthallic anhydride, nitrobenzene, methyl ethyl pyridine, toluene diisocyanate, trichloroethane, trichloroethylene, perchloro-ethylene, aniline, chlorobenzenes, dimethyl hydrazine, ethylene dibromide, toluenediamine, epichlorohydrin, ethyl chloride, ethylene dichloride, and vinyl chloride. [Pg.57]

The same reaction, carried out with conventional heating at the same temperature, took more that 6 h to give comparable yields of the products. Dihydropyrazoles were also obtained by microwave-assisted reaction of poly-substituted vinyl ketones 122 with hydrazines, followed by reaction of the unstable pyrazole 123 with electrophiles (Scheme 43) [80]. [Pg.237]

As mentioned before for other azolide reactions, acylations can be carried out with polymer-supported azolides as acylating reagents. For example, acetic acid hydrazide can be prepared with a polymer of l-acetyl-4-vinyl-imidazole/divinylbenzene (96 4) and hydrazine (no diacylation occurs when this method is used) [122]... [Pg.134]

This silyl hydrazone formation-oxidation sequence was originally developed as a practical alternative to the synthesis and oxidation of unsubstituted hydrazones by Myers and Furrow [31]. The formation of hydrazones directly from hydrazine and ketones is invariably complicated by azine formation. In contrast, silyl hydrazones can be formed cleanly from /V,/V -bis(7< rt-butyldimethylsilyl)hydrazine and aldehydes and ketones with nearly complete exclusion of azine formation. The resulting silylhydrazones undergo many of the reactions of conventional hydrazones (Wolff-Kishner reduction, oxidation to diazo intermediate, formation of geminal and vinyl iodides) with equal or greater efficiency. It is also noteworthy that application of hydrazine in this setting may also have led to cleavage of the acetate substituents. [Pg.50]

Fattah et al., utilized /3-keto vinyl ethers (e.g., 174) in the presence of hydrazine as precursors to pyrazoles (e.g., 175) [89]. Scheme 46 gives a general illustration of this reaction. [Pg.56]

Finally, fully reduced heterocycles have been prepared either from a sequential azomethine imine cycloaddition-palladium-mediated cyclization process <2003T4451>, or from the reaction of A-( l-benzotriazolylalkyU-AyV-disubstitutcd hydrazine with methyl vinyl ether <1997JOC8210>. [Pg.421]

Commercial hybrid materials, silicon-based, 73 538—540 Commercial hydrazines, physical properties of, 73 565t Commercial hydrolysis, in vinyl alcohol polymerization, 25 609, 612t Commercial immunoassays, for clinical applications, 74 140 Commercial inks, 74 320 Commercial laundering, detersive systems for, 8 413t... [Pg.202]

This Asian species is a major agricultural pest. The pheromone has been proposed to consist of three male-specific compounds, only one of which, (Z)-exo-a-bergamotenal 150, has been reported in the literature [114]. The racemic compound was synthesized starting from farnesoic acid chloride 146 (Scheme 25) [114]. Thus, the vinyl ketene prepared from acid chloride 146 underwent 2+2 cycloaddition to give bicyclic ketone 147. The ketone function was removed by reaction with hydrazine followed by treatment of the resulting hy-... [Pg.82]

For the practical design of hypersurfaces, i.e. cuts through the (3n-6)dimensional hyperspace, some hints are outlined. The main purpose, however, is to illustrate the usefulness of hypersurface calculations especially for the detection, identification and characterization of unstable molecules. Examples chosen comprise the structure of RS-C=C-SR, the relative stability of thioacroleine isomers C,H S, the structural changes accompanying the oxidation of hydrazine and some of its derivatives, the isomerization of tetrahedrane to cyclobutadiene both thermally as well as on oxidation, the predicted existence of F SS and nonexistence of CI2SS or H2SS, and, finally, some aspects of the thermal decomposition of methyl and vinyl azides. [Pg.139]

Carbonyl reagents, such as semicarbazide and phenelzine (27), are inactivators of SSAO. In a strategy that includes two inactivating structural motifs (allylamine and hydrazine), a series of allyl hydrazines including the series 28a-c as well as the fluoroallyl analogue 29 were prepared. Compounds 28a-c were potent irreversible inhibitors of SSAO, and compounds 28a,c had particularly good selectivity with respect to MAO inhibition. The presence of the vinyl fluoride in 29 had little effect on potency but did result in a loss in selectivity [82]. [Pg.674]

Examples of synthesis of five-membered heterocycles following this strategy are limited in number. An approach to 1,3,4-triazoles involves bonding of C-l and C-3 of vinyl isocyanate 150 to both nitrogen atoms of aromatic hydrazines (78JOC402) (Scheme 37). The reaction was run at room temperature and gave quantitatively regioisomer 151 or a mixture of 151 and 152 when p-nitrophenyl and phenylhydrazine, respectively, were employed. [Pg.31]

Reaction of cyanoacetic acid with formamide in hot acetic anhydride affords a product assumed to be 164. This with triethyl orthoformate gives the vinyl ether 165. The latter reacts with hydrazines to yield 166. Heating hydrazine 166 (R = H) gives pyrazolo[3,4-d]pyrimidines 167 and 168 the hydrazine 166 (R = CHsOr Ph) gives the pyrazole 169 and then 168 on heating (71JCS(C)1610). [Pg.344]

Au NPs have been synthesized in polymeric micelles composed of amphiphilic block copolymers. Poly(styrene)-block-poly(2-vinylpyridine) in toluene has been used as nanocompartments loaded with a defined amount of HAuCl4 and reduced with anhydrous hydrazine. The metal ions can be reduced in such a way that exactly one Au NP is formed in each micelle, where each particle is of equal size between 1 and 15 nm [113]. In another example, the addition of HAuCfi to the triblock copolymer (PS-b-P2VP-b-PEO) (polystyrene-block-poly-2-vinyl pyridine-block-polyethylene oxide) permits the synthesis of Au N Ps using two different routes, such as the reduction of AuC14 by electron irradiation during observation or by addition of an excess of aqueous NaBH4 solution [114]. [Pg.155]

In the latest development of his elegant work with hydrazone derivatives, Andrew Myers of Harvard reports (J. Am. Chem. Soc. 2004,126, 5436) that Sc(OTf), catalyzes the addition of l,2-bis(r-butyldimethylsilyl)hydrazine, to aldehydes and ketones to form the t-butyldimethylsilylhydrazones. Addition of tBuOH/tBuOK in DMSO to the crude hydrazone effects low temperature Wolff-Kishner reduction. Alternatively, halogenation of ketone hydrazones can lead to vinyl halides such as 11, or the 1,1-dihalo derivatives, depending on conditions. Halogenation of aldehyde hydrazones provides the 1,1-dihalo derivatives such as 13. [Pg.161]

Hydrazine gel compns contg fuel metals (such as Al, Mg, Be, etc), microdimensional fibers (such as glass, asbestos, cellulose or synthetic) and thickeners, such as polyacrylamide, Na CM-cellulose, hydroxyethyl-cellulose, poly(vinyl)aIc, poly(Me methacrylate). Thus a soft gel was prepd. It contained hydrazine 65.20, polyacrylamide 0.67, microglass fibers 0.80 Al powder 33 33%... [Pg.575]

Chemicals which can damage (a) the liver include carbon tetrachloride, paracetamol, bromobenzene, isoniazid, vinyl chloride, ethionine, galactosamine, halothane, dimethyl-nitrosamine (b) the kidney include hexachlorobutadiene, cadmium and mercuric salts, chloroform, ethylene glycol, aminoglycosides, phenacetin (c) the lung include paraquat, ipomeanol, asbestos, monocrotaline, sulfur dioxide, ozone, naphthalene (d) the nervous system include MPTP, hexane, organophosphoms compounds, 6-hydroxydopamine, isoniazid (e) the testes include cadmium, cyclophosphamide, phthalates, ethanemethane sulfonate, 1,3-dinitrobenzene (f) the heart include allylamine, adriamycin, cobalt, hydralazine, carbon disulfide (g) the blood include nitrobenzene, aniline, phenyl-hydrazine, dapsone. [Pg.430]

A series of membrane materials have been tested for the performance of water removal from hydrazine, including poly(vinyl alcohol) (PVA), ethyl cellulose, PS, and ABS (93). Contact angle measurements served to estimate the hydrophilic or hydrophobic properties. Apolar materials showed higher separation factors than polar materials. Encouraging results with respect to the performance were obtained with modified ethyl cellulose and ABS membranes. [Pg.239]


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