Potassium Acetate Solution Bisulphite

Preparation of the sulphones. Dissolve the 2 4-dinitrophenyl-sulphide in the minimum volume of warm glacial acetic acid and add 3 per cent, potassium permanganate solution with shaking as fast as decolourisation occurs. Use a 50 per cent, excess of potassium permanganate if the sulphide tends to precipitate, add more acetic acid. Just decolourise the solution with sulphur dioxide (or with sodium bisulphite or alcohol) and add 2-3 volumes of crushed ice. Filter off the sulphone, dry, and recrystaUise from alcohol. 

Benzaron (1 part) was dissolved in a very slight excess of 3% caustic soda. To this solution is gradually added a slight excess of iodine dissolved in a 25% aqueous solution of potassium iodide. The resultant solution is acidified with a 20% solution of sodium bisulphite, centrifuged, washed with water and then recrystallized in acetic acid to give of 2-ethyl-3-benzofuranyl 4-hydroxy-3,5-diiodophenyl ketone. MP 167°C. 

The acrylic component can be left undyed quite easily because it has no affinity for those direct dyes which are classified as acetate reserving. There are also many diazotized and developed direct, as well as vat dyes which will dye the cellulose only. Disperse dyes can be used for acrylonitrile fibre, but they will stain the cotton or rayon component, and clearing with a solution containing 8 oz to 1 lb of potassium permanganate and 2 oz of sulphuric acid per 100 gallons at 30 C (86 F) for 15 minutes, will probably be necessary. The oxides of manganese will subsequently have to be removed with sodium bisulphite. 

Aurin ciystallizes in fine, red needles from its solution in HOI. It is insoluble iu H.O, but soluble iu HCl, alcohol, and glacial acetic acid. It forms a colorless compound with potassium bisulphite. 

For Step II. Potassium Permanganate 11.2 g 2-(4-Chlorophenyl-3-methyl-4-metathiazanone 10 g Glacial Acetic Acid 50 ml Sodium bisulphite (saturated solution) q.s. Chloroform 100 ml Isopropyl Alcohol q.s. ... 

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