Malonic acid, sulfate

Malonic acid, sulfate TSK IC-Anion-SW, 5 pm Methanol-3 mM phthalic acid, pH 6.8 (adjusted by hexamethylenediamine) (10 90)... 

This ester (70 g) and diethyl carbonate (250 mg) were stirred at 90°C to 100°C while a solution of sodium ethoxide [from sodium (7.8 g) and ethanol (1 54 ml)] was added over 1 hr. During addition, ethanol was allowed to distill and after addition distillation was continued until the column heat temperature reached 124°C. After cooling the solution to 90°C, dimethyl sulfate (33 ml) was followed by a further 85 ml of diethyl carbonate. This solution was stirred and refluxed for 1 hr and then, when Ice cool, was diluted with water and acetic acid (10 ml). The malonate was isolated in ether and fractionally distilled to yield a fraction boiling at 148°C to 153°C/0.075 mm, identified as the alpha-methyl malonate. This was hydrolyzed by refluxing for 1 hr at 2.5N sodium hydroxide (350 ml) and alcohol (175 ml), excess alcohol was distilled and the residual suspension of sodium salt was acidified with hydrochloric acid to give a precipitate of the alpha-methyl malonic acid. This was decarboxylated by heating at 180°C to 200°Cfor 30 minutes and recrystallized from petroleum ether (BP 80°C to 100°C) to give 2-(2-fluoro-4-biphenylyl)propionic acid, MP 110°C to 111°C. 

The starting material may be produced by reacting 6-amino-2-methylthiopyrimidine with ethoxymethylene malonic acid diethyl ester. The intermediate thus produced is converted by boiling in diphenyl ether to 6-ethoxycarbonyl-2-methylthio-5-oxo-5,B-dihydropyrido-[2,3-d]pyrimidine. That is hydrolyzed by sodium hydroxide to cleave the ethoxy group and then ethylated with diethyl sulfate to give the starting material. 

FIGURE 10.7 Numbers of anthocyanins containing the various acyl moieties identified in anthocyanins. The upper dark part of each bar represents the anthocyanins reported later than 1992. cou, p-coumaric acid caf, caffeic acid fer, ferulic acid sin, sinapic acid cin, 3,5-dihydroxycinnamic acid hba, p-hydroxybenzoic acid gao, gallic acid mal, malonic acid ace, acetic acid mli, malic acid sue, succinic acid tar, tartaric acid oxa, oxalic acid sul, sulfate. 

These must be glycerol free. A solvent extraction procedure must be used prior to GC-MS [2, 5, 6]. If the sample is prepared with ion-exchange chromatography, the glycerol will remain in the neutral fraction and not be detected by GC-MS [2, 5]. Hydrochloric acid (5 N), pH paper, sodium sulfate (anhydrous), ethyl acetate (free of contaminants), diethyl ether (anhydrous, peroxide-free, and free of contaminants except 2,6-ditertbutylcresol, which is an antioxidant found in all ether), and malonic acid (26.25 mg/50 ml methanol). 

Diethyl sulfate Ethoxymethylene malonic acid diethyl ester... 

Another semidegradative synthesis is the reaction of 3-methylthio-1,2-benzodithiolium sulfate with malonic acid. It does not give, as initially thought,65 a 3-[(l,2-benzodithiol-3-ylidene) methyl]-l,2-benzodithiolium ion, but in fact a 2-(l,2-benzodithiol-3-ylidene)-2JT benzo[6]thiophene-3-thione (45).40... 

The Belousov-Zhabotinsky reaction demonstrated here is set in train by the reduction of potassium bromate to elemental bromine by malonic acid and manganese(II) sulfate this is shown by the orange coloration. The reaction of the bromine with malonic acid to give mono or dibromomalonic acid leads to decolorisation. At the same time more bromine is formed in the initial redox process, and this again replaces one or two hydrogen atoms of the malonic acid. The process is repeated many times the start reaction is inhibited by complexa-tion of the brominated malonic acid by Mn(ll) ions, so that the oscillation slowly comes to an end. ... 

Sodium iodate NalOs, 1 mol/L H2SO4, malonic acid HOOCCH2COOH, manganese(II) sulfate MnS04 H2O, soluble starch, 10 % H2O2 solution, distilled water. 

Fig. 3-86. Comparison between the retention behavior of inorganic anions and several organic carboxylic acids, respectively. - Separator column IonPac AS4 eluent 0.0028 mol/L NaHC03 + 0.0022 mol/L Na2C03 flow rate 1.6 mL/min detection suppressed conductivity injection 50 pL solute concentrations a) 1.5 ppm fluoride (1), 2 ppm chloride (2), 5 ppm orthophosphate (3) and bromide (4), 10 ppm nitrate (5), and 12.5 ppm sulfate (6), b) 5 ppm formic acid (7), 40 ppm benzoic acid (8), 20 ppm succinic acid (9), 10 ppm malonic acid (10), 20 ppm maleic acid (11), tartaric acid (12), and oxalic acid (13).

It is generally observed that the order of elution is aliphatic monocarboxylic acids, followed by aromatic monocarboxylic acids, followed by aliphatic dicarboxylic acids. Fig, 3-86, in which the retention behavior of aliphatic dicarboxylic acids is compared with that of inorganic anions, reveals that compounds such as succinic acid, malonic acid, maleic acid, and tartaric acid elute in the retention volume of nitrate and sulfate. 

Malonic acid, CH2(COOH)2 Manganese(II) sulfate, MnS04 Starch. 

Even more intriguing is the Belousov-Zhabotinskii class of oscillating reactions some of which can continue for hours. Such a reaction was first observed in 1959 by B. P. Belousov who noticed that, in stirred sulfuric acid solutions containing initially KBr03, cerium(IV) sulfate and malonic acid, CH2(C02H)2, the concentrations of Br and Ce" " underwent repeated oscillations of major proportions (e.g. tenfold changes on a time-scale which was constant but which could be varied from a few seconds to a few minutes depending on concentrations and temperature). These observations were extended by... 

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