Product filtering

Phenolsulphonephthalein (phenol red). Mix 10 g. of o-sulpho-benzoic anhydride (Section VIII,9), 14 g. of pure phenol and 10 g. of freshly fused zinc chloride in a small conical flask. Place a glass rod in the flask and heat gently over a flame to melt the phenol. Then heat the flask containing the well-stirred mixture in an oil bath at 135-140° for 4 hours. Stir from time to time, but more frequently during the first hour if the mixture froths unduly, remove the flask from the bath, cool and then resume the heating. When the reaction is complete, add 50 ml. of water, allow the water to boil and stir to disintegrate the product. Filter the crude dye with suction and wash it well with hot water. Dissolve the residue in the minimum volume of warm (60°) 20 per cent, sodium hydroxide solution, filter, and just acidify the filtrate with warm dilute hydrochloric acid (1 1). Filter the warm solution, wash with water, and dry upon filter paper. The yield of phenol red (a brilliant red powder) is 11 g. 

The turbo-tray dryer can handle materials from thick slurries [1 million (N s)/m (100,000 cP) and over] to fine powders. It is not suitable for fibrous materials which mat or for doughy or tacky materials. Thin slurries can often be handled by recycle of dry product. Filter-press cakes are granulated before feeding. Thixotropic materials are red directly from a rotary filter by scoring the cake as it leaves the drum. Pastes can be extruded onto the top shelf and subjected to a hot blast of air to make them firm and free-ffowing after one revolution. 

The purple quinizarin solution is next saturated with carbon dioxide and the precipitated quinizarin again filtered. The product is then boiled with 5 1. of a 10 per cent solution of sodium carbonate until it appears black (probably the mono-sodium salt) to dissolve the last traces of purpurin. The mixture is cooled to room temperature, filtered, and the precipitate boiled with 5 1. of 5 per cent hydrochloric acid to liberate the quinizarin. The mixture is again cooled to room temperature and the final product filtered, washed with cold water and dried at 100°. 

A. Ethyl Sodium Phthalimidoinalonate.—To a solution of 9.2 g. (0.4 gram atom) of sodium in 300 cc. of absolute alcohol at 60° is added, with efficient stirring, 126 g. (0.41 mole) of ethyl phthalimidomalonate (Org. Syn. Coll. Vol. i, 266). The mixture is rapidly chilled to 0° and the crystalline product filtered at once by suction and washed successively with two 200-cc. portions of absolute alcohol and two 200-cc. portions of ether. After first drying in a vacuum desiccator and then heating for eight hours imder 15 mm. pressure in a flask suspended in an oil bath at 145-155° (Note i), it weighs 108-III g. (82-85 per cent of the theoretical amount). 

A solution of the ketol diacetate (15 g, 0.028 mole) in toluene (200 ml) is dried by concentration to 150 ml at normal pressure. The solution is cooled to room temperature and then added with vigorous stirring to a solution of calcium turnings (4.2 g, 0.11 g-atom) in liquid ammonia (500 ml). The addition is made in 5 min, the mixture is stirred for a further 3 min, and excess calcium is then destroyed by the dropwise addition of bromobenzene ca. 4 ml). Water (5 ml) is added cautiously and the ammonia is allowed to evaporate. The toluene is removed by distillation on a steam-bath under reduced pressure and methanol (200 ml) is added to the residue, followed by a solution of potassium hydroxide (5 g) in water (10 ml). The mixture is boiled for 1 hr, water (50 ml) is added, and the mixture is warmed on the steam bath for 30 min in order to coagulate the product. Water (250 ml) and acetic acid (15 ml) are added, the mixture is cooled and the product filtered, washed thoroughly with water and dried to give 12.3 g of crude 11-ketotigogenin, mp 209-218° Md, -31°. 

The separated aqueous layer is extracted with chloroform and the eombined chloroform solution washed with water and evaporated to a volume of 10 ml in vacuo. 5 % Aqueous potassium carbonate (10 ml) is added and the mixture stirred 1 hr at room temperature. The chloroform is distilled under reduced pressure and the resulting crystalline product filtered, washed with water and methanol, and dried to give 82 mg (79 %) of the 3-ethylenedioxy derivative of cortisone acetate mp 248-260° (dec). 

E) Preparation of 2-( 1-Succinyloxyethyl)-3-Methyl-5-(2-Oxo-2,5-Dihydro-4-Furyl)Bemo[b] -Furan (409 CBj 8.65 grams of compound 3574 CB in 43 ml of pyridine are warmed for 30 minutes, on a water bath, with succinic anhydride. At the end of this, the pyridine is stripped off in vacuo. The mixture is treated with dilute sulfuric acid and with ether, the crystalline product filtered off, washed with water and with ether, and recrystallized from ethyl acetate (9.35 grams). MPq = 144°C (measured after drying at 90°C and 0.1 mm). Yield 77%. The product yields an equimolecular compound with morpholine. MPc= 136°C (from ethyl acetate). 

After being left in the refrigerator overnight the mixture, which has set solid, is triturated with 50 ml of isopropyl alcohol and the solid product filtered off and dried in vacuo over phosphorus pentoxide. 63 g (60% yield) of 1,2-diphenyl-3,5-dioxo-4-n-butyl-4-(N -methylpiper-azinomethyl)pyrazolidine are obtained, melting at 1 29°C after recrystallization from 150 ml of isopropyl alcohol. 

The products of the photodecomposition of the ferrioxalate absorb only weakly at wavelengths absorbed by ferrioxalate and therefore provide no problem with regard to a product filter effect. This can be seen from Table 2.7. 

Thiophenoxytellurine. To 0.8 g (0.002 mol) of the dichloride, 7.2 g (0.03 mol) of hydrated sodium sulphide were added and heated at 100°C for 15 min. The reaction mixture was diluted with water and the product filtered and dried (0.6 g, 96%). Recrystallization from ethanol gave pale yellow needles, m.p. 122-123.5°C. 

The hydrated oxide is prepared by hydrolysis of antimony pentachloride or by acidification of potassium hexahydroxoantimonate(V), KSb(OH)6 [12208-13-8]. The product, filtered and air dried at ambient temperature has approximate composition 86205 3.5H2O. It may be also prepared by oxidation of antimony trioxide with nitric acid. 

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