Sodium pyruvate, solution preparation

Diethyl oxalate (29.2 g, 0.20mol) and 4-bromo-2-nitrotoluene (21.6 g, O.lOmol) were added to a cooled solution of sodium cthoxide prepared from sodium (4.6 g, 0.20 mol) and ethanol (90 ml). The mixture was stirred overnight and then refluxed for 10 min. Water (30 ml) was added and the solution refluxed for 2h to effect hydrolysis of the pyruvate ester. The solution was cooled and concentrated in vacuo. The precipitate was washed with ether and dried. The salt was dissolved in water (300 ml) and acidified with cone. HCl. The precipitate was collected, washed with water, dried and recrystallizcd from hexane-EtOAc to give 15.2 g of product. 

A solution of Grignard reactive (prepared from 247 g of o-bromoanisole and 31.6 g of magnesium in 1500 ml of ether) is added dropwise to a solution of 91 g of diphenyl pyruvic acid in ether. The mixture is refluxed for 2 hours. After cooling to the reaction mixture is added 5% hydrochloric acid and the product is extracted with 5% solution of sodium hydroxide. a-(o-Anisyl)-p,15-diphenyl lactic acid is precipitated by addition of concentrated hydrochloric acid yield 62 g, melting point 194-195°C. 

Xanthan Gum occurs as a cream colored powder. It is a high-molecular-weight polysaccharide gum produced by a pure-culture fermentation of a carbohydrate with Xanthomonas campestris, purified by recovery with isopropyl alcohol, dried, and milled. It contains D-glucose and D-mannose as the dominant hexose units, along with D-glucuronic acid and pyruvic acid, and it is prepared as the sodium, potassium, or calcium salt. It is readily soluble in hot or cold water, but it is insoluble in alcohol. Its solutions are neutral. 

Oxidative degradation of substituted pyruvic acids is accomplished by treating an aqueous solution of the sodium salt with 30% hydrogen peroxide (Superoxol) at 0-15°. Good descriptions have been published for the preparations of o-hydroxyphenylacetic acid (34%), 3,4-dim.ethoxy-phenylacetic acid (60%), m-chlorophenylacetic acid (57%), and o-nitro-phenylacetic acid. ... 

A mixture of 4.53 g of-aminophenylacetic acid (0.03 mol), 7.9 g pyruvic acid (0.09 mol), and 200 mL water (3.5% deuterium) was boiled under reflux for 3 h. A homogeneous solution was formed within a few minutes after the mixture began to boil. On completion of the reaction, benzaldehyde was removed by distillation through a declining condenser and extracted from the distillate with several small portions of chloroform. The aqueous portion of the distillate and the aqueous reaction mixture were reserved. After drying the chloroform solution over sodium sulfate, the solvent was evaporated and the residual benzaldehyde was converted into the phenylhydrazone by treatment with phenylhydrazine in 50% alcoholic solution. After recrystallization from 60% alcohol, the yield of benzaldehyde phenylhydrazone was 4.3. 4 g, m.p. 155.5-157°C for various preparations. 

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