Precipitated products

Osmium s voice In the original patent a continuous, 27 hours extraction with hot toluene was used. This is very impractical. I recommend the following after extraction and removal of the ex traction solvent, dissolve the crude product in 400 - 450 ml hot toluene, put that solution in a beaker and cool it for at least 2 hours in an ice bath. Filter the precipitated product, wash with about 100 ml ice-cold toluene ahd dry at 70°C or in a desiccator to constant weight. Mp. 132.5-134.0°C.]... 

Magaldrate is prepared by precipitation from aqueous solutions of sodium or potassium aluminate and a magnesium salt under controlled conditions of concentration and temperature. The precipitated product is collected by filtration, washed to remove soluble by-products, and dried. 

For the preparation of mixtures of mercurous and mercuric chlorides used to control turf-fungus diseases, the precipitated product of the second method may be mixed with the required amount of mercuric chloride. Alternatively, the chamber material, if the ratios of mercurous and mercuric chloride are correct, may be used directiy. 

Soluble sodium sibcate glass sobd and bquid (anhydrous). Excludes quantities consumed in the manufacture of meta-, ortho-, and sesquisibcates. Includes quantities consumed in the manufacture of glass powder, hydrated glasses, and precipitated products. Shipment figures include unspecified amounts shipped to other plants for the manufacture of meta-, ortho-, or sesquisibcates. 

Because of its extreme insolubiUty, barium sulfate is not toxic the usual antidote for poisonous barium compounds is to convert them to barium sulfate by administering sodium or magnesium sulfate. In medicine, barium sulfate is widely used as an x-ray contrast medium (see Imaging TECHNOLOGY X-RAY technology). It is also used in photographic papers, filler for plastics, and in concrete as a radiation shield. Commercially, barium sulfate is sold both as natural barite ore and as a precipitated product. Blanc fixe is also used in making white sidewall mbber tires or in other mbber appHcations. 

Pluess-Staufer), and Pfizer Inc. The principal U.S. producers of precipitated products are Mississippi Lime Co. and Pfizer Inc. 

At this point there may be a lumpy, dark-brown material mixed with the orange-brown crude precipitated product. There appears to be no need to break up the liunps. 

If no precautions are observed, the reaction mixture rapidly darkens after acidification when exposed to air. The sulfur dioxide generated upon acidification of the sodium bisulfite largely prevents this discoloration however, the precipitated product should be collected without delay of more than a few hours. The sulfur dioxide used in the wash water also protects the product. 

Lime Soda. If carbon dioxide is in solution in water and calcium hydroxide is added, the resulting precipitation product is CaCO this can be removed by sedimentation. 

Cyanoandrost-5-ene-3jS,17-diol 3-Acetate Acetic acid (385 ml) is added during a 40 min period at 10° to a stirred mixture of 60 g of 3) -liydroxy-androst-5-en-17-one acetate and 360 g of potassium cyanide in 2 liters of alcohol. The mixture is stirred for 1 hr at 10° and then for 2 hr at room temperature. After dilution with water the precipitated product is collected by filtration, washed with 3 liters of 2 % acetic acid and dried at room temperature. The yield of epimeric cyanohydrins (mp 124° dec [ajj, —93°) is essentially quantitative. 

The reaction mixture is stirred at 0° for 3 hr and is then allowed to stand at room temperature for 24 hr. The precipitated product is collected by filtration and crystallized from ethanol to give 3-methoxy-D-homo-estra-l,3,5(10)-trien-17a-one (96 1.0 g) mp 138.5-139.5°. Goldberg and Studer report mp 138.5-139.5°." ... 

Ncold water (400 ml) and stirred until the precipitated product turned granular (fifteen minutes). The crude product was collected, washed with cold water, and dried. Crystallization from Skellysolve B with charcoal treatment gave colorless crystals (6.65 g, 58%), MP 149°C to 150°C. The product was recrystallized twice from Skellysolve B to give ( )-6[Pg.355]

The moiten mass is then poured into ethanol at 96°C, the solution cooled down to 10°C and the precipitated product separated by centrifugation. The resulting product is dissolved in the minimum quantity of warm water and the solution poured into ethanol. 

The cold solution was then allowed to stand overnight and all crystalline material filtered through a sintered glass filter. The filtrate was treated with an additional 300 ml of concentrated hydrochloric acid to yield a heavy white precipitate. The precipitate was filtered, dried and combined with the Initial precipitate obtained as described above. The combined precipitated product, 3A-dihydroxy-N-[3-(4-hydroxyphenyl)-1-methyl-n-propyl-/ henethylamine hydrochloride, had a melting point of about 184°Cto 186°C after recrystallization from boiling 4N hydrochloric acid. 

A solution of 14 g of 21 -hydroxypregnane-3,20-dione and of 14 g of recrystallized succinic anhydride in 140 ml of dry pyridine was allowed to stand at room temperature for 18 hours, then cooled in an ice bath and poured in a fine stream into 1.5 liters of ice water. Excess pyridine was neutralized with 3N hydrochloric acid and the solution further diluted with 2 liters of ice water. The precipitated product was filtered, washed with water and dried in vacuo at 50°C affording 18 g of solid MP 192°C to 195 t. Recrystallization of a small sample afforded analytically pure material, MP 200°C. 

An aqueous syrup of 1,4 3,6-dlanhydro-D-glucitol is slowly added to a cooled mixture of HNO3 and H2M4. After standing a few minutes the mixture is poured into cold water and the precipitated product is collected and recrystallized from ethanol. 

A) A mixture of 333 parts of 4-(1 -piperazinyDphenol dihydrobromide, 11.2 parts of acetic acid anhydride, 42 parts of potassium carbonate and 300 parts of 1,4-dioxane is stirred and refluxed for 3 days. The reaction mixture is filtered and the filtrate is evaporated. The solid residue is stirred in water and sodium hydrogen carbonate is added. The whole is stirred for 30 minutes. The precipitated product is filtered off and dissolved in a diluted hydrochloric acid solution. The solution is extracted with trichloromethane. The acid aqueous phase is separated and neutralized with ammonium hydroxide. The product is filtered off and crystallized from ethanol, yielding 5.7 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine MP 181.3°C. 

A mixture of 5.2 parts of 4-chloro-3-nitrobenzophenone, 5 parts of ammonia, 72 parts of methanol and 13 parts of sulfolane is heated overnight at 125°C in a sealed tube. The reaction mixture is evaporated in vacuo. The semisolld residue is boiled in 100 parts of a diluted hydrochloric acid solution. After cooling, the precipitated product Is filtered off and dissolved in chloroform. The chloroform phase is dried and evaporated. The residue is crystallized from toluene, yielding 4-amino-3-nitrobenzophenone MP 141°C. 

The whole is slowly heated to 85°C and stirred at this temperature for 45 minutes. The reaction mixture is cooled and the precipitated product is filtered off. It is washed successively with water and ethanol, dried and crystallized from a mixture of acetic acid and methanol, yielding methyl N-[5(6)-benzoyl-2-benzimidazolyl] carbamate MP 288.5°C. 

A solution of 1.7 g of 2-hydroxymethyl-3-benzyloxy-(1-hydroxy-2-tert-butyl-aminoethyl)py-ridine in 30 ml of methanol containing 1.2 ml of water is shaken with 700 mg of 5% palladium-onatmospheric pressure. In 17 minutes the theoretical amount of hydrogen has been consumed and the catalyst is filtered. Concentration of the filtrate under reduced pressure provides 1.4 g of the crude product as an oil. Ethanol (5 ml) Is added to the residual oil followed by 6 ml of 1.75N ethanolic hydrogen chloride solution and, finally, by 5 ml of Isopropyl ether. The precipitated product is filtered and washed with isopropyl ether containing 20% ethanol, 1.35 g, melting point 182 (dec.). 

C. The precipitated product is filtered, dried and recrystallized from ethyl acetate to give 5-fluoro-2-methyl-1-(p-methylsulfinylbenzylidene)-3-indenylacetic acid. Upon repeated recrystallization from ethylacetate there is obtained cis-5-fluoro-2-methyl-1-(p-methylsulfinyl-benzylidene)-3-indenylacetic acid (MP 184° to 186°C). 

A mixture of betaine 13 (0.28 g, 1.3 mmol) and MeOH (2 mL) was warmed on a steam bath until the red color of the solution had faded to pale yellow (10-15 min). The solution was cooled and diluted with a small amount of H20 and the precipitated product, 1,5-dimethyl-6-phenyl-l H-, 2-diazcpin-4(7//)-one (14), was collected yield 0.22g (79%) mp 73-75 C (Et20/pentane). 

A suspension of 6-chloro-2-(chloromethyl)-4-phcnylquinazoline 3-oxide (8 40 g, 0.13 mol) in 15% NH3/ EtOH (400 mL, large excess) was stirred at 20 C for 5h. The precipitated product was filtered off and washed with H20, followed by Et20 yield 24 g (60%) pale-yellow prisms mp 255-256 C (McOH). 

The benzodiazepine 4-oxide 5 (15 g, 50 mmol) in warm dioxane (200 mL) was cooled to 20 C and hydrogenated at atmospheric pressure in the presence of Raney nickel (20 g). The theoretical volume of hydrogen had been absorbed after 2 h. The precipitated product was dissolved by heating tile mixture and the catalyst was removed by filtration. The product separated yield 14.1 g (99.5%) yellowish plates mp 240-241 C (acetone). 

A solution of 4-hydroxycoumarin (1.62 g. 10 mmol) and a benzene-1,2-diamine (10 mmol) in xylene (50 mL) was refluxed for 3 h. The solution was cooled and the precipitated product was collected, washed with Et20 or hexane and recrystallized (MeCN or dioxane). 

This compound was prepared by heating benzene-1,2-diamine (2.16 g, 20 mmol) and the appropriate derivative of diethyl malonate (10 mmol) in 1,2,4-trichlorobenzene (15 rnL) at 190—195 "C for 2 h. The resulting solution was cooled and the precipitated product was collected and washed with benzene, followed by petroleum ether.253... 

K2C03 (1.38g, 10 mmol) was added to a stired solution of a, V,/V -diacctyi-2-(chloro-2-nitrophcnylsui-fanyl)phenylhydrazine (3.79 g, 10 mmol) in DMF (20mL) and the mixture was healed under reflux for 15 min. It was cooled, poured into H2() and the precipitated product 3 (62-81%) was rccrystallized (benzene). 

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