Cobalt(III) ammine complexes containing acetylpyruvic acid derivatives. I. Preparation and characterization of the complexes

1974 ◽  
Vol 27 (6) ◽  
pp. 1161 ◽  
Author(s):  
JG Hughes ◽  
MJ O'Conner
Keyword(s):  
Aqueous Solution ◽  
Methyl Ester ◽  
Potassium Iodide ◽  
Sodium Salt ◽  
Ammine Complexes ◽  
Hydrolysis Of

When the [Co(en)2(H2O)2]3+ ion is allowed to react with the sodium salt of acetylpyruvic acid or its methyl ester in aqueous solution at 80�C, hydrolysis of the β-diketone occurs and [Co(en)2(ox)]I2 is isolated by the addition of potassium iodide. The method of preparation and characterization of [Co(en)2(ap)]I and [Co(en)2(map)]I2 are described. Reactions involving the corresponding tetraammine and cis-α-triethylenetetramine cobalt(111) complexes are also described.

Characterization of the end products of the hydrolysis of iron in aqueous solution

1994 ◽  
Vol 88 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Juan A. Jaén ◽  
Ezequiel Acevedo ◽  
Marcia González
Keyword(s):  
Aqueous Solution ◽  
End Products ◽  
Hydrolysis Of

scholarly journals CATALYTIC SYNTHESIS OF GLYCOLIC ACID AND ITS METHYL ESTER FROM GLYOXAL

2021 ◽  
Vol 86 (12) ◽  
pp. 134-145
Author(s):  
Svitlana Levytska ◽  
Artur Mylin
Keyword(s):  
Aqueous Solution ◽  
Methyl Ester ◽  
Glycolic Acid ◽  
Mixed Oxides ◽  
Raw Materials ◽  
Chloroacetic Acid ◽  
Bactericidal Properties ◽  
Basic Catalysts ◽  
Methyl Glycolate ◽  
Hydrolysis Of

Glycolic acid is practically non-toxic to humans, has bactericidal properties and a weak odor, which makes it widely used in food (as a flavoring and preservative) textile (as a dye and tanning agent), cosmetics and pharmaceuticals (as a keratolytic and a skin care agen). Glycolic acid can also be converted to biodegradable polymer with good mechanical properties and excellent biocompatibility, wich is used for different medical applications. In industry, glycolic acid is obtained by carbonylation of formaldehyde using as catalysts quite aggressive acids (H2SO4, HCl, HF), hydrolysis of hydroxyacetonitrile under the influence of acids (H2SO3, H3PO3) or the enzyme nitrilase and saponification of chloroacetic acid with a double excess of alkali (NaOH, KOH). In addition to the non-ecological nature of used raw materials for this process there is a problem associated of purification of the product especially from homogeneous catalysts. The process of obtaining glycolic acid and its methyl ester from glyoxal over a number of solid acid and basic catalysts based on mixed oxides of aluminum, tin, titanium, zirconium, and magnesium has been studied. In study, commercially available 40% aqueous solution of glyoxal, anhydrous glyoxal trimer (Sigma-Aldrich, 95%) and methanol (99%, Merck) were used. Catalytic experiments were carried out in rotated steel autoclave (60 rpm) for 0.5–5 hours at temperatures of 100–170 °C. It is shown that the synthesized oxide catalysts after 5 h of reaction at 100 °C provide up to 98% conversion of an aqueous solution of glyoxal to glycolic acid with a selectivity of 83–100%.It was found that over the studied basic catalysts the undesirable oligomerization process of the formed glycolic acid occurred to a lesser extent and as a result the yield of monoglycolic acid was much higher (60–69%) than over acid catalysts (28–40%). The most selective MgO-ZrO2 catalyst after 1 h of the reaction at 150 °C of methanolicglyoxal solution provides almost 100% yield of methyl glycolate.

2-Diethylaminoethyl esters of 1,3-disubstituted propane-2-carboxylic acids

1987 ◽  
Vol 52 (10) ◽  
pp. 2534-2544 ◽  
Author(s):  
Vladimír Valenta ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Vladimír Miller ◽  
Marie Vlková ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Methyl Ester ◽  
Potassium Carbonate ◽  
Sodium Salt ◽  
Dimethyl Sulfate ◽  
Crystal Form ◽  
Ester Exchange ◽  
Melting Crystal ◽  
Pharmacological Screening ◽  
Hydrolysis Of

Alkaline hydrolysis of diethyl 1-(tetrahydro-2-furyl)-3-(1-naphthyl)propane-2,2-dicarboxylate (IV) gave the crude acid V which was purified via the dipotassium salt and was obtained as the homogeneous higher melting crystal form. Its thermic decarboxylation yielded the acid II as a mixture of two racemates (38 : 62); crystallization led to the almost homogeneous racemate B (10 : 90). Reaction of the sodium salt of II with dimethyl sulfate in methanol gave the methyl ester III which afforded by ester exchange with 2-diethylaminoethanol the ester I (mixture of two racemates 34 : 66). 2-Diethylaminoethyl 1,3-bis(1-naphthyl)propane-2-carboxylate (VII) was synthesized in three steps from diethyl (1-naphthylmethyl)malonate. Ester X was obtained from 1,3-bis(tetrahydro-2-furyl)propane-2-carboxylic acid by treatment with 2-diethylaminoethyl chloride in boiling 2-propanol in the presence of potassium carbonate. The acid V gave similarly the diester VI. 2-Diethylaminoethyl esters I, VI, VII, and X were transformed to the hydrogen oxalates. Pharmacological screening showed for the diester VI hypotensive, spasmolytic, antiarrhythmic, and antitussic activity.

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