Anhydrid, acetic silicic

Li etal. (2000a, 2001b) smdied the flammability of wood modified with acetic or propionic anhydrides, finding that this parameter, as determined by limiting oxygen index (LOI), was the same as that found for unmodified wood. Samples were also prepared which were impregnated with sodium silicate prior to anhydride modification. The latter treatment resulted in a decrease in flammability, as shown by an increase in the LOI of the wood. 

A suspension of 300 mg of adriamycin-14-valerate hydrochloride in 20 ml of ethyl acetate was treated with 0.45 ml of trifluoroacetic anhydride in small portions over a few minutes until all solids had dissolved. The solution was mixed immediately with equal portions of water and chloroform (total volume 100 ml). The chloroform layer was separated and washed once with water and twice with pH 7 aqueous buffer. The chloroform solution was dried over sodium sulfate and then was evaporated to dryness under reduced pressure. The residue was dissolved in 25 ml of methanol, and the resulting solution was heated at reflux for 5 minutes, then cooled and evaporated to dryness. The residue was redissolved in 4 ml of chloroform, and the crude product was precipitated by the addition of 20 ml of petroleum ether (b.p. 38°-49°C). The crude material was purified by chromatography on a silicic acid column. 

A mixture of 36 (392.6 mg, 0.369 mmol) and Pd/C (10% Pd, 390 rag) in dioxane (3 mL) was shaken under hydrogen (1 atm). After 4 h (TLC CHClj-MeOH-HjO, 40 10 1) the mixture was filtered, and the solution was evaporated and coevaporated with toluene several times. The residue was dissolved in pyridine (5 mL) and acetic anhydride (1 mL). After 15 h at room temperature (TLC toluene-acetone, 2 1), toluene (5 mL) was added, and the mixture was evaporated and coevaporated with toluene in vacuo several times. Chromatography on silic el (petroleum ether-acetone, 3 1) yielded an ot/p mixture (276.3 g, 91%, a/p = 32 1) as a syrup. A small quantity of the pure a-anomer 37 was obtained by rechromatography on silica gel (petroleum ether-acetone, 3 1) [a], +33.7° (c 1, CHCI3) the NMR data were in agreement with the reported [50] data. 

SODIUM SILICATE (6834-92-0 1344-09-8) NajSiOj Violent reaction with fluorine, lithium. Reacts with water, forming a strong base. Aqueous solution reacts violently with acids and is incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, nitrates, phenols, vinyl acetate. Attacks aluminum and zinc in the presence... 

DIFLUOROPHOSPHORIC ACID (13779-41-4) Reacts with moisture in air, forming hydrogen fluoride. Reacts with water, steam, forming hydrofluoric acid. Aqueous solution incompatible with sulfuric acid, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, organic anhydrides, isocyanates, vinyl acetate. Attacks glass and other siliceous materials. Attacks metals in the presence of moisture. 

By altering the reaction conditions, a preponderance of either product may be produced as desired. Vinyl acetate, which is used for making polymers, and ethylidene diacetate, which is an intermediate for the manufacture of acetic anhydride, are produced on a large scale. The reaction may be applied to other carboxylic adds and acetylene derivatives. Strong acids, such as sulfuric, methane di- and trisulfonic, and phosphoric acids, are catalysts. They may be used in conjunction with mercury salts. Other catalysts which have been disclosed for the reaction include boron trifiuoride and the salts of various metals, such as zinc silicate, zinc acetate, and mercuric phosphate. The addition may be effected in the vapor phase... 

Alginic acid s-Amyl acetate Bayberry (Myrica cerifera) wax Beeswax s-Butyl acetate C12-18 acid triglyceride Carboxymethylcellulose sodium Casein Cellulose acetate Ethylene/MA copolymer Milk protein Perchloroethylene Polyvinyl alcohol Sodium silicate Starch Styrene/MA copolymer Tristearin sizing compounds Calcium bromide Sodium borate sizing ingredient, paper Dodecenylsuccinic anhydride Rosin Sodium stearate Stearic acid sizing paper Dextrin... 

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