Periodic acid-Sodium bisulfite

Periodic acid-Sodium bisulfite, HjI06-NaHS03. 

The catalyst was removed by filtration. The filtrate was diluted to about 18 liters, and was acidified with 15 ml concentrated hydrochloric acid. With vigorous stirring, 1,152 ml N KICI2 solution were run into the diluted filtrate over a period of about 20 to 30 minutes. A solid precipitate was formed, and was filtered off after about six hours. The sol id material was washed with water, with sodium bisulfite solution, and again with water. It was dissolved in aqueous ammonium hydroxide solution, the solution was filtered, and the filtrate was acidified with concentrated hydrochloric acid containing a small amount of sodium bisulfite. After a short time, the precipitate formed was filtered with suction, washed with water, and dried. 

A solution of 192 g 3-acetylamino-2,4,6-triiodophenol, sodium (0.35 mol) in 350 ml di-methylacetamide, was mixed with 107.5 g 3-(2-iodoethoxy)-2-ethylpropionic acid ethyl ester (0.35 mol) at 90°C with stirring over a period of about 20 to 30 minutes. Stirring was continued while the mixture was held at 95°C to 100°C for 16 hours. The solvent was then removed by distillation in a vacuum, and the residue was poured into 4,000 ml water. The solid precipitate formed was recovered and washed with water, dilute sodium carbonate solution, dilute sodium bisulfite solution, and again with much water. The ethyl ester was obtained in a yield of 220 g (90%). When recrystallized from 75% aqueous ethanol, it melted at 80°C to 86°C. 

A solution of 5.0 g of a-ethyl-(3-(aminophenyl)propionic acid in 100 ml of water containing 5 ml of concentrated hydrochloric acid was added over a period of h hour to a stirred solution of 3.2 ml of Iodine monochioride in 25 ml of water and 25 ml of concentrated hydrochloric acid heated to 60°C. After addition was complete, the heating was continued for h hour longer at 60° to 70°C. A black oil separated which gradually solidified. The mixture was then cooled and sodium bisulfite was added to decolorize. Recrystallization of the product from methanol gave about 8 g of a-ethyl-(3-(2,4,6-triiodo-3-aminophenyl-pro-pionic acid, MP 147° to 150°C. The product could be further purified by precipitation of its morpholine salt from ether solution and regeneration of the free amino acid by treatment of a methanol solution of the morpholine salt with sulfur dioxide. The pure amino acid had the MP 155° to 156.5°C (corr). 

The following alternative procedure may be used to prepare a solution of disodium hydroxylaminedisulfonate. Sodium nitrite (15 g., 0.217 mole) and 41.6 g. (0.40 mole) of sodium bisulfite are added to 250 g. of ice. With stirring, 22.5 ml. (0.40 mole) of acetic acid is added all at once and the mixture is stirred for 90 minutes in an ice hath. At the end of the stirring period the reaction solution is pH 5 and a potassium iodide-starch test is negative. A solution of 50 g. (0.47 mole) of sodium carbonate in water (total volume 250 ml.) is added. This buffered solution of disodium hydroxylaminedisulfonate may be used for electrolytic oxidation. 

A. Preparation of the cuprous chloride solution. A solution of 1250 g. (5 mols.) of crystallized copper sulfate and 325 g. (5.6 mols.) of sodium chloride in 4 1. of hot water is prepared in a x 2-1. flask. The flask is fitted with a mechanical stirrer, and an alkaline solution of sodium sulfite (265 g. of sodium bisulfite and 17 5 g. of sodium hydroxide in 2 1. of water) is added during a period of five to ten minutes. The mixture is allowed to cool to room temperature and washed by decantation. The cuprous chloride is obtained as a white powder, which, however, darkens on exposure to the air. The crude product is dissolved in 2 kg. of commercial 28 per cent hydrochloric acid (sp. gr. 1.14) and the solution is used in the following preparation. 

More definite evidence for the transient existence of the un-cyclized l-(jS-aminoethyl)-3,4-benzoquinones has been obtained recently by Kodja and Bouchilloux,77 78 who noted that a transient yellow color (Amax ca. 385 mp) was occasionally observed during the enzymic oxidations of catecholamines (particularly in unbuffered systems at low temperatures). This phenomenon was probably due to the formation of the transient o-quinones. (The absorption maximum of o-benzoquinone, the effective chromophore of the open-chain quinones, is known to occur at ca. 390 mp.79) An absorption maximum at 390 mp is characteristic of the formation of the dopa-quinone chromophore during oxidation of small C -terminal tyrosine peptides in the presence of tyrosinase.37 48 Similar spectroscopic features were observed when the oxidations were carried out with lead dioxide in sulfuric acid solutions (pH> 1). If the initial oxidation was carried out for a short period of time, it was possible to regenerate the original catecholamines by reduction (e.g. with sodium bisulfite, potassium iodide, and zinc powder) and to show that the 385 mp peak disappeared.77,78 Kodja and Bouchilloux were also able to identify 2,4-dinitrophenylhydrazones of several of the intermediate non-cyclized quinones by paper chromatography and spectroscopy (Amax n weakly acid solution ca. 350 mp with a shoulder at ca. 410 mp).77,78... 

Small Quantities. Work in the fume hood. Wear eye protection, nitrile rubber gloves and laboratory coat. Place 6.0 g (7 mL, 0.107 mol) of acrolein in a 1 L, three-necked, round-bottom flask equipped with a thermometer, stirrer, and dropping funnel. Over a period of 10 minutes, add 50 mL of a solution of 63 g (0.4 mol) of potassium permanganate in 700 mL of water. If the purple color is not discharged, warm the mixture on steam bath until it becomes brown. Add the remainder of the permanganate solution at such a rate that the temperature does not exceed 45°C. When addition is complete, heat the mixture on the steam bath to 70-80°C, while stirring, for 1 hour. Cool the mixture to room temperature, and acidify to pH 1 with 3 M sulfuric acid (16 mL of concentrated acid cautiously added to 84 mL of cold water). Add solid sodium bisulfite, while stirring, until a colorless solution is produced. Wash the solution into the drain with water.7... 

Wear eye protection, laboratory coat, and rubber gloves. Dissolve the aniline (1 mL) in 50 mL of 3 M sulfuric acid (prepared by slowly adding 8 mL of concentrated sulfuric acid to 21 mL of water). Weigh 10 g of potassium permanganate and stir small portions of the solid into the aniline solution over a period of about 1 hour. Stir the mixture at room temperature for 48 hours, and then neutralize the solution by adding solid sodium carbonate or a 10% solution of sodium hydroxide. Add solid sodium bisulfite until solution is colorless. Decant the clear liquid into the drain and discard any brown solid with regular refuse.11,12... 

The method of preparation of (AL)-mandelic acid has been described by Vogel in great detail [3]. 25 g of sodium cyanide is dissolved in 100 mL of water, and 53 g of purified benzylaldehyde is added. 335 mL of a saturated solution of sodium bisulfite is added to the benzylaldehyde/cyanide solution with stirring over a period of 10-15 minutes. During the first half of the addition, the temperature of the reaction mixture is kept low through the addition of 150 g of crushed ice. At the end of the reaction period, the solution is transferred to a separatory funnel, and the layer of crude mandelonitrile is separated. 

Procedure Set-up the apparatus as illustrated below, and then place 100 grams (3.5 oz.) of powdered sodium bisulfite into the flask as illustrated, and then place 100 grams (3.5 oz.) of concentrated hydrochloric acid or concentrated Muriatic acid into the addition funnel as illustrated. Thereafter, gradually drip the hydrochloric acid onto the sodium bisulfite over a period of about 30 to 90 minutes. During the acid addition, the sulfur dioxide gas will be steadily evolved and will carry over. 

Preparation of Fremy s salt a freshly prepared sodium bisulfite solution (100 ml) is added to a mixture of sodium nitrite (345 g) and ice (200 g) in a 1-1 beaker. On addition of 20 ml of glacial acetic acid, the reaction mixture turns black. Concentrated ammonium hydroxide (25 ml) is added and the mixture is cooled in an ice bath. A 0.2 M solution (400ml) of potassium permanganate is added dropwise over 1 h and the black precipitate which forms is immediately removed by filtration. A saturated solution of potassium chloride (250 ml) is added slowly over a 45-min period while the filtrate is gently stirred in an ice water bath. The precipitate that forms is collected by filtration and washed successively with a saturated solution of potassium chloride and methanol, each containing 5% of concentrated ammonium hydroxide and, finally, with acetone. Fremy s salt should be stored in a desiccator over calcium oxide. A small amount of ammonium carbonate in a desiccator is also very effective in protecting Fremy s salt against deeomposition. 

A solution of sodium hypobromite, prepared by dissolving 42 g (1.05 mol) of sodium hydroxide in 200 mL of water and adding 15 mL (47 g, 0.29 mol) of bromine at 0 C, is added over a 30-min period to a stirred solution of 15.0 g (0.066 mol) of 4-(p-methoxyphenyl)acetophenone in 150 mL of dioxane. During the addition, the temperature is allowed to rise to 35-40 °C. After being stirred for an additional 15 min, the mixture is treated with enough sodium bisulfite to destroy the excess of sodium hypobromite. Water (1 L) is added, and 200 mL of water is distilled off to remove the bromoform and some dioxane. Acidification of the hot solution and subsequent cooling yields 13.8 g (91%) of 4-(p-methoxyphenyl)benzoic acid, mp 247-248 °C. 

Into the cell is then placed a solution of 15 g. sodium sulfate. 15. g. boric acid and 14 g. of salicylic acid (0.1 mole), just neutralized with the calculated amount of sodium hydroxide. The solution is then diluted to, 175 cc. All the boric acid not dissolve in this quantity of solution, but is kept in suspension by means of rapid mechanical stirring. The cell is placed in a cooling mixture, and when the temperature reaches 15° to 18° the current is turned on. A temperature of 15° to 18° is maintained throughout the experiment. A current of 3 amp. (6 amp. per sq. dm.) is then passed through the solution for a period of 1 hr. 55 min., which is slightly more than the calculated amount (5.4 amp.-hr.) necessary to reduce the salicylic acid to salicylic aldehyde. During the electrolysis 20 g. sodium bisulfite are added at the rate of about 1.5 g. every 10 min. It has been found best not to begin the addition of the sodium bisulfite until the electrolysis has been started about 5 min, since the bisulfite reduced to sulfur when added to soon, or too rapidly thereafter. 

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