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Aliphatic and heterocyclic

The reaction is applicable to the preparation of amines from amides of aliphatic aromatic, aryl-aliphatic and heterocyclic acids. A further example is given in Section IV,170 in connexion with the preparation of anthranilic acid from phthal-imide. It may be mentioned that for aliphatic monoamides containing more than eight carbon atoms aqueous alkaline hypohalite gives poor yields of the amines. Good results are obtained by treatment of the amide (C > 8) in methanol with sodium methoxide and bromine, followed by hydrolysis of the resulting N-alkyl methyl carbamate ... [Pg.413]

Figure 4.6 Metabolism of unsaturated aliphatic and heterocyclic compounds via epoxides. Figure 4.6 Metabolism of unsaturated aliphatic and heterocyclic compounds via epoxides.
When a two-fold molar excess of amine at reaction temperature of about 100° (an autoclave is employed for the low-boiling primary aliphatic amine ) was used, yields of 86-95% were quite common for the alkylation of a number of aliphatic and heterocyclic secondary amines, and 6-75% for several primary aliphatic amine. The yields of some of the 2-armnoethanethio) obtained by this procedure are recorded in Table 16. [Pg.311]

A coordination polymer such as (65) proves to have exemplary thermal and chemical stability and it has been used as the solid phase for separating a variety of aliphatic and heterocyclic bases. Retention volumes remained constant after many hours use at 100 °C.98... [Pg.560]

J oshi and coworkers reported the first catalytic oxidation of thiols using an iron(III) complex (Table 3.4) [153]. Fem-EDTA proved to be an excellent catalyst for the oxidation of a variety of aromatic, aliphatic and heterocyclic thiols under alkaline conditions using molecular oxygen as the primary oxidant. Aromatic thiols were found to be more reactive than aliphatic thiols, for which the reactivity was strongly dependent upon the pH of the medium. [Pg.112]

Since several studies identified the aliphatic and heterocyclic sulfur compounds as being important to cooked-beef flavor (9-11). the present report focuses upon a few key sulfur compounds that contribute to flavor of cooked meat as they change with time and temperature. Previous work has been directed to obtaining reliable correlation of sensory panel data with objective instrumental data describing meat flavor deterioration on storage (1). The present study is targeted toward obtaining a reliable, objective assay... [Pg.452]

Standards of typical meat flavor sulfur aliphatics and heterocyclics were made from 5 ng/pl to 500 ng/pl in hexane to determine response factors as well as reproducibility in the flame photometric detector. Background sulfur compounds were checked in concentrated reagent blanks. [Pg.453]

The co-ordination chemistry of vanadium(n) has been extended by the preparation and characterization of complexes with aliphatic and heterocyclic amines.365 Intense charge-transfer bands dominate the reflectance spectrum of the dark-red or red-brown V(amine)4X2 complexes (amine = py, / - and y-picoline X = Cl, Br, or I) but assignments of some of the d-d transitions indicate a trans-dihalogeno structure this is consistent with the spin-only magnetic moments ca. 3.87 BM. In contrast, the yellow V(amine)2Br2 complexes obtained with / - and y-picoline exhibit considerable antiferromagnetic interaction indicative of polymeric bromine-bridged structures. [Pg.48]

More than 130 different organic chemicals are currently employed as herbicides in the U.S. All of the main families of organic compounds are represented aromatic, aliphatic, and heterocyclic. Herbicidal activity is found in a variety of classes of compounds haloaliphatic, phenoxy, and benzoic acids carbamates dinitroanilines acetanilides amino triazines quaternary pyridinium salts uracils and ureas. A few selected key examples are reviewed below. [Pg.47]

Many water-insoluble ketones, aliphatic, aryl aliphatic, and heterocyclic, respond favorably to treatment with ammonium formate or formamide to form with subsequent hydrolysis the primary amines. A typical procedure for the synthesis of a-phenylethylamine (66%) from acetophenone and ammonium formate has been applied to many other ketones (65-84%). Nuclear alkoxyl, halo, and nitro groups are not disturbed. The reaction with formamide as the reducing agent is catalyzed by ammonium formate, ammonium sulfate, or magnesium chloride. ... [Pg.337]

Certain amines are readily prepared by the reduction of aromatic, aryl aliphatic, and heterocyclic amines. For example, aniline is reduced to cyclohexylamine by high-pressure hydrogenation in the presence of Raney nickel catalyst or a cobalt oxide-calcium oxide catalyst. The reaction occurs at a temperature above 200°, where condensation of the primary amine also takes place, viz., 2CjHiiNHj — (CjHn),NH + NH,. If this side reaction is repressed by the presence of dicyclohexylamine at the start of the reaction, a 94% yield of cyclohexylamine is obtained. Hydrogenation of aryl aliphatic amines proceeds more readily, occurring at moderate temperatures and pressures over platinum catalyst in glacial acetic acid. Other reductions using this catalyst are best performed on the amines in the form of their hydrochlorides. ... [Pg.782]

R = R = R = H) was heated with aliphatic and heterocyclic 1,2-diamines, diazabiphenylenes were not obtained. However, one diamine, diaminomaleonitrile, did condense with 132 to form benzo-2,5-diazocine... [Pg.208]

Diphenylnitrilimine has been investigated extensively it undergoes cycloaddition to the C=N bond in aromatic, aliphatic, and heterocyclic Schiff bases to give good to excellent yields of various tetrasubstituted triazolines (53) (64CB1085 66USP3278545). Cycloaddition to oximes, hy-drazones, and imidates yields unstable triazolines 54-56 that aromatize spontaneously (65CB642). [Pg.199]

Aliphatic and heterocyclic aldehydes give mainly 1 1 adducts, formulated as ... [Pg.219]

According to Brewster a net P-helicity (P,P,M,P,M) and a net M-helicity (M,M,P,M,P) can be assigned to P-twistane 3b) and M-twistane 3a), respectively. The first synthesis of optically active twistane has been reported by Nakazaki . He postulated — as did shortly afterwards Tichy — an absolute configuration for (-l-)-twistane, which was corrected later by Tichy as follows (-l-)-5Z corresponds to iR,3R,6R,8R), )-3b corresponds to (1S,3S,6S,8S) But even today there are some uncertainties with respect to the absolute configuration in the twistane series . Numerous aliphatic and heterocyclic molecules having helical twistane skeletons have been synthesized and characterized stereotopologically. Some of them are shown in Table 5 together with some chiroptical data. [Pg.23]

Aromatic, aliphatic and heterocyclic acid chlorides all give high yields of ketones, [1,4] addition not being observed with a,3-unsaturated acid chlorides. This leads to a potentially very useful synthesis of divinyl ketones since, in contrast to Lewis acid catalyzed acylations of alkenes, under the neutral reaction conditions for the acylation of alkenylstannanes, cyclizations to cyclopentenones do not occur. [Pg.727]

HAS are weaker quenchers of 02 than aromatic amines [208]. Extensive quenching studies were performed with aliphatic and heterocyclic amines [209]. Data obtained in the inhibition of the self-sensitized photo-oxidation of rubrene revealed that the quenching efficiency of unhindered amines may be correlated with their ionization potentials. A low ionization potential means a better quenching activity. Substitution on the a-carbon atom to nitrogen by alkyls reduces the quenching rate predicted from the ionization potential [208, 209]. The sensitivity of 02 quenching to steric effects may be exemplified with quenching rate constants kq(in dm3 mol was used as a standard. [Pg.140]

Both 1,2-dihydro- and 2,4-dihydropyrazol-3-ones are known to substitute the chlorine atom of aliphatic and heterocyclic chloro imines and aliphatic trihalogenomethylimines. Nucleophilic substitution of 2-chlorobenzo[l,3]thiazole 550 by C-2 of l,2-dihydropyrazol-3-one 549 requires heating at 120 °C in DMF with a strong base such as sodium hydride. The product 551 was obtained in only 22% yield (88JHC543) (Scheme 165). [Pg.230]

Halogens at positions 4 of pyrazol-3-ones can be displaced by both aliphatic and heterocyclic carbon and nitrogen nucleophiles and can be oxidized by lead(II)... [Pg.238]

The effects of catalyst structure (secondary and tertiary aliphatic and heterocyclic amines), solvent, temperature, and substrate structure on rates and products of prototropic isomerizations of /3,y-unsaturated nitriles and esters were studied by Miaihe and Vessiere" . [Pg.447]

Some other research results concern extraction and transport of nucleotides through the single salt binding of a cationic host with a phosphate moiety. Simple (poly)amines and more complicated aliphatic and heterocyclic nitrogen compounds were employed [170,181—183]. Obviously, they lack selectivity over different nucleobase components. However, they may discriminate among mono-, di-, and triphosphates. And, most important,... [Pg.127]

Anodic cyanation of tertiary aliphatic and heterocyclic amines in sodium cyanide-aqueous methanol solutions using platinum electrodes takes place a-to the nitrogen atom to form the a-cyano-amines in reasonable yields. ... [Pg.147]

Copper(II) acetate in MeOH containing morpholine gives o-benzoquinone as the primary product [13,65]. Aryloxy radicals are formed in a side-reaction only. Copper(I)-amine systems in non-polar solvents afford aryloxy radicals from phenols, and the corresponding coupling products [66-69]. Copper(II) complexes of aliphatic and heterocyclic amines are known to catalyze the oxidation of substituted phenols [70-72]. The basicity and steric properties of the ligand influence the nature of oxidation products. [Pg.224]

Another example of carbonylative Sonogashira coupling reactions with iodi-nium iodide and 1-alkynes was published by Ma and colleagues in 2001 [32]. Under mild conditions, iodine-substituted alkynones were produced in good yields (Scheme 5.9). Both aromatic, aliphatic and heterocyclic terminal acetylenes can be applied as their substrates. [Pg.98]


See other pages where Aliphatic and heterocyclic is mentioned: [Pg.52]    [Pg.76]    [Pg.492]    [Pg.649]    [Pg.124]    [Pg.79]    [Pg.474]    [Pg.61]    [Pg.27]    [Pg.229]    [Pg.375]    [Pg.61]    [Pg.70]    [Pg.343]    [Pg.343]    [Pg.2331]    [Pg.208]    [Pg.141]    [Pg.174]   


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