Malonic aldehyde

Scheme 1. Principle of cyanine dye synthesis leading to trimethine (n = l), pentamethine (n = 2) and heptamethine (n = 3) chromophores. Structures comprising indolic subunits are usually named indocarbocyanine, indodicarbocyanine and indotricarbocyanine, respectively. Formic acid, malonic aldehyde, glutaconic aldehyde are used in their protected dianUide or orthoester form. They can be applied as substituted derivatives to introduce residues into the polymethine unit. The indolic substructure might bear further residues or annelated aromatic rings...

In Sprague-Dawley rats treated orally with 50, 75, 100 or 150 mg/kg bw acrylonitrile, hepatic nonprotein sulfhydryl concentration was significantly decreased after 30 min (Silver et al., 1982). Twenty-four hours after administration of 150 mg/kg bw, focal liver necrosis was observed. In isolated rat hepatocytes, acrylonitrile (1 mM) treatment resulted in the formation of thiobarbituric acid-positive products (a test for malon-aldehyde) and in depletion of non-protein sulfhydryl groups, but did not affect markedly the viability of the cells (Nerudova et al., 1988). 

For an intramolecular OH O fragment, a strong hydrogen bond corresponds to R < 2.55 A and V < 8 kcal/mol. In this case, C and ft are close to unity and this corresponds to an intermediate case between the sudden and adiabatic regimes. Examples of such systems are malon-aldehyde, tropolon and its derivatives, and the hydrogenoxalate anion. 

There are, of course, many carbonyl compounds formed by hydrolytic or oxidative deteriorations of lipid constituents, and most of these are potentially capable of entering into Mai Hard reactions with proteins. One such product is reputedly malon-aldehyde (26) (Figure 10). 

Hydroxylamin N,0-Diacetyl-N-propanoyl- E5, 785 (Anhydrid + NaO-Ac/R -CH2 - N02) Malon-aldehyd-saure Acetamino-methyl- -methylester E21c, 2549, 2550... 

Treatment of /j-methoxyphenylethylamine with a stoichiometric amount of CuCOAc) and in the presence of a catalytic amount of Pd(OAc)2 produced a 3,4-diarylpyrrole via an unexpected three-component cyclization process <06JACS12046>. Another three-component sequence was exploited to prepare 5-aryl-2-oxopyrrole derivatives via cyclocondensation reactions between malonates, aldehydes, and primary amines <06T6018>. 

Copper-containing lUCDs (6,7) became popular because local inflammatory reactions in the endometrium are more marked and the contraceptive effect is thus more pronounced (SEDA-21, 234) (8). In addition, copper ions released from lUCDs reach concentrations in the luminal fluids of the genital tract that are toxic to spermatozoa and embryos. The ability of copper to induce the generation of free radicals and the formation of malon-aldehyde may be involved in its contraceptive effect. 

Cyanomethyl groups can be a convenient source of pyridine rings treatment with acetic anhydride-perchloric acid [3934], acetonitrile-aluminium chloride [2884], Vilsmeier reagent [2727], a 1,3-diketone (or its enol) [2714] and malon-aldehyde bisacetal [2714] have been used successfully and sometimes give high yields. Pyrido[4,3-A]indoles have been reviewed [2535]. 

Synonyms/Trade Names Malonic aldehyde Malonodialdehyde Propanedial 1,3-Propanedial [Note Pure Malonaldehyde is unstable and may be used as its sodium salt ] ... 

Reaction of an aqueous ethanol solution of the sodium enolate of 1-adamantyl-malonic aldehyde with benzenediazonium chloride gave (680 67%), which was hydrolysed to (681 86%). This is the first instance that the postulated intermediate (680) has been isolated in the Japp-Klingemann reaction of a l,3-dialdehyde. ° ... 

Previous dietary treatment with selenium (1 ppm) decreased the hepatic content of malonic aldehyde of the fiver of rats fed CCI4 (2.5 ml/kg body weight) to nearly the normal values (Bene-DETTi et al. 1974). 

Thiophen Analogues of Quinoline and Related Compounds.—Convenient methods for the synthesis of the thiophen analogues of quinoline have been worked out. By the condensation of 2- and 3-thienylanunonium hexachlorostannates with malonic aldehyde tetraethyl acetal, thieno-[2,3-6]pyridine (538) and thieno[3,2-6]pyridine (539) were obtained in 44% and 77% yields. With other /5-dicarbonyl compotmds, substituted derivatives were obtained. Thus, acetoacetaldehyde dimethyl acetal gave... 

This assay is basically used to appoint the lipid oxidation. It is an older test for receiving the oxidation status of fats spectrophotometricaUy. Thereby the aldehydes, which are generated by the autoxi-dation of unsaturated fatty acids, are converted into red or yellow colorimeters with TEA. Eut it is also used for the determination of the potency of antioxidants with thiobarbituric acid reactive substances (TEARS). Thereby the antioxidant activity is measmed by the inhibition of the lipid oxidation. It concerns the spectrophotometric detection of malonic aldehyde, one of the secondary lipid peroxidation products, which generates a pink pigment with TEA (Ruberto et al., 2000 Varda-Unlii etal.,2003). 

Malonic Aldehyde, This dialdehyde is preferentially formed by autoxidation of fatty acids with three or more double bonds. The compound is odorless. In food it may be bound to proteins by a double condensation, crosslinking the proteins (cf. 3.7.2.4.3). Malonic aldehyde is formed from a-linolenic acid by a modified reaction pathway, as outlined under the formation of hydroperoxide-epidioxide (cf. 3.7.2.1.3). However, a bicyclic compound is formed here as an intermediary product that readily fragments to malonic aldehyde ... 

The hydrolysis of phenyl propagyl aldehyde diethyl acetal (V) is realized at 363 — 373 K with simultaneous distillation. In the case of the diacetals of unstable dialdehydes, e.g., malon aldehyde (IX), hydrolysis occurs in the presence of aniline hydrochloride, and 3-amilino-propenylanilinium chloride (X) is formed. 

FIGURE 6.1 (a) One-dimensional interpolation of the potential V[qo(z)] as a function of the parameter z along the instanton path qo(z) for three ab initio methods in the case of malon-aldehyde. The points represent the ab initio data. The lines are obtained by piecewise cubic interpolation, (b) One-dimensional interpolation of the elements of Hessian 9 V [q(z)]/9 along the instanton path for MP2/cc-pVDZ ab initio method. Two examples are shown. (Taken from Reference [122] with permission.)... 

SCHEME 1.54 Cascade Michael-aldol reactions with malonate aldehyde. 

Moreover, upon refluxing in 1,2-dichloroethane, electrophilic attack of the N-vinyl moiety by the cationic complex DMF/POCI3 may lead to diadducts A, which on boiling in H20/Na0Ac afford pyrrole-2-carbaldehydes and malonic aldehyde through unstable dialdehyde intermediate B (Scheme 2.133). 

Thiophen Analogues of Quinoline.— Interest in the chemistry of thieno-pyridines is continuing. Thieno[3,2-b]pyridine has been prepared in 80% yield through the zinc-chloride-catalysed condensation of 3-aminothiophen hydrochloride with malonic aldehyde acetal. Reaction of the 2-amino-3-benzylthiophen (425) with l-nitro-2,2-bis(methylmercapto)ethylene (426) gave the thieno[2,3-b]pyndine derivative (427) in 29% yield. 5-Ethylthieno-... 

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