Malonic Acid Reaction Research Articles

Features of the reaction of malonic acid with piperazine in a combustion regime

Features of the reaction of malonic acid with piperazine in a combustion regime

Preparation and synthetic utilization of 3-(adenin-9-yl)-2-hydroxyalkanoic acids and their derivatives

Condensation of adenine and its substituted derivatives with 1,1-dialkoxy-2-bromoalkanes afforded substituted 2-(adenin-9-yl)-1,1-dialkoxyalkanes I and IV. Acid hydrolysis of I or IV, followed by reaction with alkali metal cyanides and acid hydrolysis, gave substituted 3-(adenin-9-yl)-2-hydroxyalkanoic acids II, Vand VI. Methyl esters of these compounds (VIII) were converted into 3-(adenin-9-yl)alkane-1,2-diols IX by reduction with sodium borohydride. 3-(Adenin-9-yl)-2-methoxypropanoic acid (XVII) was obtained by oxidation of 9-(3-hydroxy-2-methoxypropyl)adenine (XVI) with sodium periodate; 4-(adenin-9-yl)-2-(S)-hydroxybutanoic acid (XXVII) was synthesized by oxidation of 9-(S)-(2-tetrahydropyranyloxy-4-hydroxybutyl)adenine (XXV), prepared from diethyl L-malate. Acid hydrolysis of XXV afforded 9-(S)-(2,4-dihydroxybutyl)adenine (XXVI). 4-(Adenin-9-yl)-3-hydroxypentanoic acid (XXIX) was obtained by reaction of malonic acid with 2-(adenin-9-yl)-1,1-diethoxypropane (IVa) in water.

Kinetic investigation of the bromate–ascorbic acid–malonic acid system

AbstractAccording to our experiments the bromide ion concentration exhibits in the bromate–ascorbic acid–malonic acid–perchloric acid system three extrema as a function of time. To describe this peculiar phenomenon, the kinetics of four component reactions have been studied separately. The following rate equations were obtained:Bromate–ascorbic acid reaction: Bromate–bromide ion reaction: Bromide–ascorbic acid reaction: Bromine–malonic acid reaction: k4 = 6 × 10−3 s−1, k‐4 ≥ 1.7 × 103 s−1, k5 ≥ 1 × 107M−1 · s−1Taking into account the stoichiometry of the component reactions and using these rate equations, the concentration versus time curves of the composite system were calculated. Although the agreement is not as good as in the case of the component reactions, it is remarkable that this kinetic structure exhibits the three extrema found.

On Mode Interactions in Reaction Diffusion Equation with Nearly Degenerate Bifurcations

Chemical reactions as an open system have been investigated both theoretically and experimentally since nonlinear and non-equilibrium physics became one of current branches of physics. A typical example of these is the Belousov-Zhabotinsky reaction; a cerium ion catalyzes oxidation reaction of malonic acid by acidic bromate. In this reaction it is observed that the ratio of concentrations of Ce'+ and Ce3 '· may temporally oscillate, form a spatially periodic pattern or move as a wave under appropriate conditions. These phenomena are called dissipative structures. The concept of dissipative structures may help us to understand from a unified viewpoint various phenomena in open systems such as the Benard convection, 11 the laser oscillation,21 the temporal rhythm in living systems besides chemical reacting systems.3J Several nonlinear reaction diffusion equations4l have already been studied both theoretically and numerically. It is shown that they have generally the desired solutions to explain those dissipative structures which appear in the B-Z reaction system except the wave mode. The characteristic features of these equations are as follows. First, they exhibit the bifurcation of solution. Secondly their solutions will approach finally to certain states irrespective of initial conditions. Thirdly, bifurcating modes may mutually interact in vanous ·ways. The first and the second have already been studied. Therefore, we study the third in this paper.

Meldrum's acid and its analogs

2-Substituted or 2,2-disubstituted 4,6-dioxo-1,3-dioxanes, which are analogs of Meldrum's acid and were obtained by reaction of malonic acid with acetic anhydride and the appropriate carbonyl compound in the presence of sulfuric acid, exist in solution preferably in a single form according to the PMR and 13C NMR spectral data. Fluctuation of the CH2 group is not observed. The mass spectra are characteristic and are distinguished by splitting out of the carbonyl compound from the molecular ion or successive splitting out of CO2 and ketene molecules. The Meldrum acid analogs do not affect plant growth but have a depressive effect on the central nervous system of animals and low toxicity.

Volumes of ionization of dicarboxylic acids in aqueous solution from density measurements at 25°C

The densities of aqueous solutions of the dicarboxylic acids [CH2]n(COOH)2(n= 0 – 5) and their mono- and di-socium salts have been measured at 25°C and used to calculate their apparent molal volumes. These have been used to obtain volumes of ionization for both dissociation reactions. The volumes of ionization, except for the second dissociation reaction of malonic acid, lie within the limits –6.7 to –14.2 cm3 mol–1. The upper limit, –6.7 cm3 mol–1, seems to originate from the volume change accompanying the dissociating proton only, and the lower limit arises since the charge of the acid anion only affects the hydration sheaths of the nearest CH2-groups.

Codonocarpus alkaloids—IV : Synthesis of 2-methoxy-2′-ethoxy-4-[2-(tetramethylenecarbamoyl)ethyl]-5′-[2-(propylcarbamoyl)ethyl]diphenyl ether

Synthesis of the title compound was accomplished by coupling the iodonium bromide ( 3) of 4-ethoxybenzaldehyde with methyl hydroferulate ( 4) to 2-methoxy-2′-ethoxy-4-(methyl β-propionate)-5′-formyldiphenyl ether ( 5) which was converted to the pyrrolidinyl amide 6, and then the aryl aldehyde group was extended to a n-propyl β-propionamide unit via the Knoevenagel malonic acid reaction through the trans-cinnamic acid 7 followed by hydrogenation and amide formation with n-propylamine.

Oscillatory Oxidation of Malonic Acid by Bromate 3. CO2 and BrO3 --Titration

Abstract The reaction of malonic acid and bromate in the presence of catalytic amounts of cerious ion under oscillating conditions in sulphuric acid was investigated. After two hours reaction time 26 mM bromate were consumed and 42 mM CO2 produced. No formic acid was detected. Furthermore, 14C-tracer experiments suggest that malonic acid is first brominated and subsequently decarboxylated.

Vinyl polymerization initiated by ceric ion reducing agent systems in sulfuric acid medium

AbstractPolymerization of the monomers, methyl acrylate (MA) and methyl methacrylate (MMA) was carried out in sulfuric acid medium at 15°C. With the redox initiator system, ceric ammonium sulfate–malonic acid. There was no induction period, and a steady state was attained in a short time. There was found to be no polymerization even after 1 hr. in the absence of the reducing agent R. The initiation was by the radical produced from the Ce4+–malonic acid reaction. The rate of monomer disappearance was proportional to [M]1.5, [R]0.5, and [Ce4+]0.3–0.5, and the rate of ceric disappearance was directly proportional to [R] and [Ce4+]. Chain lengths of the polymers were directly proportional to [M] and inversely to [R]1/2 and [Ce4+]1/2. The experimental results were explained by a kinetic scheme involving the following steps: (a) oxidation of the substrate to give the primary radical which reacts with Ce4+ to give the products, (b) initiation by the primary radical, (c) propagation, and (d) termination of the growing polymer radicals by the mutual type. For the polymerization of acrylonitrile (AN) by the redox system, ceric ammonium sulfate–cyclohexanone (CH), in sulfuric acid at 15°C., the scheme was modified to include linear type of termination by Ce4+, along with the mutual termination to explain the results especially under conditions with [Ce4+] ≥ [CH].

Effect of Bromine Derivatives of Malonic Acid on the Oscillating Reaction of Malonic Acid, Cerium Ions and Bromate

WHEN malonic acid, ceric sulphate and potassium bromate are dissolved in dilute sulphuric acid there occurs an oscillating chemical reaction which manifests itself by an oscillation of the light absorption which is caused by ceric ions (317 mµ) and an oscillation of the rate of evolution of carbon dioxide. An oscillation of the potential of a platinum electrode dipped into the solution can also be measured1. Fig. 1 shows the light absorption at 317 mµ as a function of time in a solution of the above mentioned substances. The curve divides itself into four distinct sections: (a) disappearance of ceric ions; (b) reappearance of ceric ions; (c) stationary concentration of ceric ions; (d) oscillation. The cessation of the oscillation (not shown in Fig. 1) is usually abrupt, and the ceric ion concentration persists at the minimal value attained in the oscillation.

A new synthesis of substituted barbituric acids

Malonic acid and substituted malonic acids react under mild conditions with N,N′-disubstituted carbodiimides to give barbiturates. The reaction of malonic acid and ethylmalonic acid with N,N′-di-p-tolycarbodiimide, however, follows a different course.

Studies on the Synthesis of Amino Acids by the Schmidt Reaction. VI. Synthesis of Methionine Sulfoximine Analogs

Toxic substance, which is contained in wheat flour treated with nitrogen trichloride and causing dogs to suffer a fit like epilepsy, was separated by Bently, et al. Although it had been confirmed that this substance is a specific compound having O atom and NH group attached to S atom, its analogs have not yet been synthesized. Therefore, several of its analogs were prepared by the reaction of (2-alkylthioethyl) malonic acid with hydrazoic acid.