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Aldehydes glyoxal

Dinitrophenyl-hydrazine has been successfully employed in the analysis of simple aldehydes, substituted aldehydes, glyoxal and gluteraldehyde (43-45), all the isomers of the C3 to C7 aliphatic ketones (44,45) and in the determination of formaldehyde in tobacco smoke (46). [Pg.244]

Ethyl alcohol Acet-aldehyde Glyoxal Di-aldehyde... [Pg.261]

The steps of the ethylene glycol oxidation mechanism (3) are formation of glycolic aldehyde, glyoxal or glycolic acid, glyoxylic acid, oxalic acid and finally, formic acid is obtained. For this reason, in the next experiment, the effect of adding glyoxal and oxalic acid in... [Pg.609]

Reaction with Other Aldehydes. Polyacrylamide reacts with glyoxal [107-22-2], C2H2O2, under mild alkaline conditions to yield a polymer with pendant aldehyde fiinctionahty. [Pg.141]

Carbon—nitrogen double bonds in imines, hydrazones, oximes, nitrones, azines, and substituted diazomethanes can be cleaved, yielding mainly ketones, aldehydes and/or carboxyHc acids. Ozonation of acetylene gives primarily glyoxal. With substituted compounds, carboxyHc acids and dicarbonyl compounds are obtained for instance, stearoHc acid yields mainly azelaic acid, and a smaH amount of 9,10-diketostearic acid. [Pg.493]

A variation involves the reaction of benzylamines with glyoxal hemiacetal (168). Cyclization of the intermediate (35) with sulfuric acid produces the same isoquinoline as that obtained from the Schiff base derived from an aromatic aldehyde and aminoacetal. This method has proved especially useful for the synthesis of 1-substituted isoquinolines. [Pg.397]

Aromatic aldehydes 1 can undergo a condensation reaction to form a-hydroxy ketones 2 (also called benzoins) upon treatment with cyanide anions.This reaction, which is called benzoin condensation, works by that particular procedure with certain aromatic aldehydes and with glyoxals (RCOCHO). [Pg.37]

The isomer of isoproterenol in which both aromatic hydroxyl groups are situated meta to the side chain also exhibits bron-chiodilating activity. Oxidation of 3,5-dimethoxyacetophenone by means of selenium dioxide affords the glyoxal derivative (15). Treatment of the aldehyde with isopropylamine in the presence of... [Pg.64]

Preparation of the key tropine is achieved by any one of several variations on the method first developed by Robinson, which involves reaction of a primary amine with dihydroxyacetone and glyoxal. Reduction of the carbonyl group in the product (86) followed by acylation affords the aminoester (88). Transesterification with ester aldehyde 89... [Pg.160]

Polar C=Y double bonds (Y = NR, O, S) with electrophilic carbon have been added to suifinic acids under formation of sulfones. As in the preceding section one must distinguish between carbonyl groups and their derivatives on the one hand, and carboxylic acids (possessing leaving groups at the electrophilic carbon) on the other. Aldehydes " of sufficient reactivity—especially mono-substituted glyoxals - —and their aryl or arylsulfonyl imines have been added to suifinic acids (in a reversible equilibrium) to yield a-hydroxy or a-amino sulfones the latter could also be obtained from the former in the presence of primary amines (equation 26). [Pg.176]

Polyvinyl alcohols may be applied as such or in crosslinked form [90]. Crosslinkers can be aldehydes (e.g., formaldehyde, acetaldehyde, glyoxal, glutaraldehyde), to form acetals, maleic acid or oxalic acid to form cross-linked ester bridges, or others (e.g., dimethylurea, polyacrolein, diisocyanate, divinyl sulfonate) [89,91]. [Pg.14]

Fi vre 17-15. Glyoxal. Low molecular aldehydes may form hydrates that act as complex forming agents. [Pg.256]

As already discussed for aldol and Robinson annulation reactions, proline is also a catalyst for enantioselective Mannich reactions. Proline effectively catalyzes the reactions of aldehydes such as 3-methylbutanal and hexanal with /V-arylimines of ethyl glyoxalate.196 These reactions show 2,3-syn selectivity, although the products with small alkyl groups tend to isomerize to the anti isomer. [Pg.143]

A cross-coupling reaction of aldehydes with a-diketones proceeded in the presence of water to give the corresponding adducts in moderate to good yield. It is possible to use the substrates such as phenyl-glyoxal monohydrate, aqueous methylglyoxal, formalin, and aqueous a-chloroacetaldehyde for this reaction.330... [Pg.281]

The coupling of enals and glyoxals was realized by hydrogen-mediated reaction with the cationic Rh complex and PI13P [35]. The intermediate aldehyde enolates derived via Rh-catalyzed hydrogenation were trapped with glyoxals to form (l-hydroxy-y-kclo-aldchydes, which were treated sequentially with hydrazine to give pyridazines in a one-pot transformation to provide, for example, a 62% yield of 72 (Scheme 21). [Pg.127]


See other pages where Aldehydes glyoxal is mentioned: [Pg.1520]    [Pg.100]    [Pg.261]    [Pg.1733]    [Pg.423]    [Pg.100]    [Pg.322]    [Pg.220]    [Pg.5]    [Pg.1520]    [Pg.100]    [Pg.261]    [Pg.1733]    [Pg.423]    [Pg.100]    [Pg.322]    [Pg.220]    [Pg.5]    [Pg.261]    [Pg.134]    [Pg.209]    [Pg.10]    [Pg.20]    [Pg.20]    [Pg.19]    [Pg.180]    [Pg.257]    [Pg.311]    [Pg.157]    [Pg.96]    [Pg.406]    [Pg.22]    [Pg.37]    [Pg.105]    [Pg.712]    [Pg.338]    [Pg.1243]    [Pg.580]    [Pg.17]    [Pg.131]    [Pg.159]    [Pg.866]    [Pg.105]    [Pg.801]   
See also in sourсe #XX -- [ Pg.176 ]




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Aldehydes and Glyoxals

Glyoxalate

Glyoxalic

Glyoxals

Glyoxals from aldehydes

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