Acid Oxalate Salt

Chemical Designations - Synonyms Potassium acid oxalate Salt acetosella Salt of sorrel Chemical Formula KHC2O4. 

Di-methyl aniline, CeHs—N(CH3)2, is a liquid boiling at the same point as the mono-methyl compound with which it is obtained by the ordinary method of preparation and from which it may be separated by the method just described. It forms well crystallized salts, especially the double salt with platinum chloride, viz., CeHs—N(CH3)2.HCL-PtCh. This compound crystalhzes, with two molecules of water, in ruby colored prisms, which, on loss of water, become reddish-yellow plates. The acid oxalate salt, CeHs—N(CH3)2.(COOH)2, forms large rectangular plates melting at 139°. With nitrous acid the reaction is the one characteristic of aromatic tertiary amines. 

Potassium Binoxalate. Potassium acid oxalate salt of sorrel sal acetoseila. C2HK04 mol wt 128.13. C 18.75%, H 0,79%, K 30.51%, O 49.95%. KOOCCOOH. Incorrectly soft of lemon". The same synonyms apply to potassium tetraoxalate. 

Crystallizes from water in large colourless prisms containing 2H2O. It is poisonous, causing paralysis of the nervous system m.p. 101 C (hydrate), 189°C (anhydrous), sublimes 157°C. It occurs as the free acid in beet leaves, and as potassium hydrogen oxalate in wood sorrel and rhubarb. Commercially, oxalic acid is made from sodium methanoate. This is obtained from anhydrous NaOH with CO at 150-200°C and 7-10 atm. At lower pressure sodium oxalate formed from the sodium salt the acid is readily liberated by sulphuric acid. Oxalic acid is also obtained as a by-product in the manufacture of citric acid and by the oxidation of carbohydrates with nitric acid in presence of V2O5. 

The b.p. under diminished pressure has been given as 80-81°/18 mm. To obtain a very pure sample of the amine, dissolve 1 part (by weight) of the above product with a sohitiuii of 1-04 parts of crystallised oxalic acid in 8 parts of hot water, add a little deculeiirisiiig carbon, and tilter. The liltered solution deposits crystals uf the acid oxalate about o g. of tliis salt remains in each 100 ml. of... 

Beyond pharmaceutical screening activity developed on aminothiazoles derivatives, some studies at the molecular level were performed. Thus 2-aminothiazole was shown to inhibit thiamine biosynthesis (941). Nrridazole (419) affects iron metabohsm (850). The dehydrase for 5-aminolevulinic acid of mouse liver is inhibited by 2-amino-4-(iS-hydroxy-ethyl)thiazole (420) (942) (Scheme 239). l-Phenyl-3-(2-thiazolyl)thiourea (421) is a dopamine fS-hydroxylase inhibitor (943). Compound 422 inhibits the enzyme activity of 3, 5 -nucleotide phosphodiesterase (944). The oxalate salt of 423, an analog of levamisole 424 (945) (Scheme 240),... 

Potassium Hydrogen Oxalate. Potassium acid oxalate [127-95-7], KHC2O4, mol wt 146.15, exists as a monohydrate [6100-03 ]. It is of historical interest because it is the salt of sorrel found in vegetation and the first oxalate isolated. 

Cobalt(II) oxalate [814-89-1], C0C2O4, is a pink to white crystalline material that absorbs moisture to form the dihydrate. It precipitates as the tetrahydrate on reaction of cobalt salt solutions and oxaUc acid or alkaline oxalates. The material is insoluble in water, but dissolves in acid, ammonium salt solutions, and ammonia solution. It is used in the production of cobalt powders for metallurgy and catalysis, and is a stabilizer for hydrogen cyanide. 

When a carrier is impregnated with a solution, where the catalyst deposits will depend on the rate of diffusion and the rate of adsorption on the carrier. Many studies have been made of Pt deposition from chloroplatinic acid (HgPtClg) with a variety of acids and salts as coim-pregnants. HCl results in uniform deposition of Pt. Citric or oxalic acid drive the Pt to the interior. HF coimpregnant produces an egg white profile. Photographs show such varied distributions in a single pellet. 

Potassium tetraoxaiate (2H2O) [oxalic acid hemipotassium salt] [6100-20-5 (2H2O) 127-96-8 (anhydr)] M 254.2. Crystd from water below 50°. Dried below 60° at atmospheric pressure. 

If very pure amine is desired the product described above is dissolved with 1.04 parts of crystalline oxalic acid in eight parts of hot water. After clarification with Norite, the filtered solution on cooling deposits crystals of the acid oxalate. About 5 g. of the salt remains in each 100 cc. of the mother liquor most of this can be obtained by evaporation and further crystallization. The amine is liberated from the pure oxalate with potassium hydroxide, distilled with steam, and purified as described above. When a known amount of amine is desired in water solution (as for optical resolution) a weighed amount of the (anhydrous) oxalate is decomposed and the amine is distilled quantitatively with steam. 

Chemical Designations - Synonyms Ammonium Oxalate Hydrate Diammonium Oxalate Oxalic Acid, Diammonium Salt Chemical Formula (NH,)2C204 H20. 

Chemical Designations - Synonyms Ferrous oxalate dihydrate, Ferrox, Iron protoxalate. Oxalic acid (ferrous salt) Chemical Eormula FeC204 2H20. 

Klee-salz, n. salt of sorrel (potassium hydrogen oxalate), -samenol, n. cloverseed oil. kleesauer, a. of or combined with oxalic acid, oxalate of. 

H- and 3//-Azepines are generally unstable in aqueous acid solution and the few examples of simple azepinium salts, namely perchlorates,77 bromides,105 picrates35201 and a solitary iodide,105 have been prepared under nonaqueous conditions. The fractional crystallization of oxalate salts has been used for the separation of mixtures of 4- and 6-substituted 3f/-azepines,66 and 3,6-di-tm-butyl- and 2,5-di-tert-butyl-3//-azepine, on treatment with tetrafluoroboric acid in acetonitrile, are converted quantitatively into their crystalline tetrafluoroboratc salts.70... 

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