Boric acid, fluoro

Boric acid, fluoro-, 101 Boromycin, 96 Boron, 81-101 as ligand, 99 Boron complexes anionic, 90-97 antibiotics, 101 applications, 101 cationic, 97 chelates, 89... 

This reaction is commonly achieved by diazotization of the amine in fluoro-boric acid, followed by decomposition of the diazonium salt (Schiemann reaction).Thus, l-amino-4-methylestra-l,3,5(10)-trien-17-one (50) is converted to the fluoro derivative (51) in 29% yield. The synthesis of 3-fluoroestra-l,3,5(10)-triene-17-one (55) from estrone proceeds via (52) and (53)... 

Fluor-, of or combined with fluorine, fluoro-, fluo-, fluoride of (see instances following),. ammonium, n. ammonium fluoride, -an-thenchinon, n. fluoranthenequinone. -anti-mon, n. antimony fluoride, -arson, n. arsenic fluoride, -baryum, n. barium fluoride, -benzol, n. fluorobensene, fluobenaene. -bor, n. boron fluoride. -borsMure, /. fluo-boric acid. -brom, n. bromine fluoride, -chrom, n. chromium fluoride, -eisen, n. iron fluoride. 

A limited number of pure substances are available from NIST, primarily clini-cally-relevant compounds such as cholesterol, urea, uric acid, creatinine, glucose, cortisol, tripalmitin, and bilirubin (NIST SRM website). These compounds are certified for purity (greater than 99 %) and are used as primary calibrants in definitive methods for these clinical analytes (see below). Several additional pure substances are available for specific applications such as microchemistry, i.e. elemental composition (acetanilide, anisic acid, cystine nicotinic acid, o-bromobenzoic acid, p-fluoro-benzoic acid, m-chlorobenzoic acid), polarimetric standards (sucrose and dextrose), acidimetric standard (benzoic acid and boric acid). Only three pure substance NIST RMs are available for environmental contaminants, namely the chlorinated pesticides, lindane, 4,4 -DDT, and 4,4 -DDE. 

Unsaturated amines are hydrogenated at the multiple bonds by catalytic hydrogenation over any catalyst. The double bond in indole was saturated in catalytic hydrogenation over platinum dioxide in ethanol containing fluoro-boric acid and indoline was obtained in greater than 85% yield [456. AUylic amines such as allylpiperidine are also reduced by sodium in liquid ammonia in the presence of methanol (yield 75%) [709. ... 

Many (hydr)oxides have been deposited by slowing down natural hydrolysis, usually by complexation (e.g., AgO from an alkaline triethanolamine-com-plexed silver bath). Highly-acidic cations will readily hydrolyse even under acidic conditions. Fluoro-complexes of some of these (e.g., Ti, Si) can be controllably hydrolyzed by addition of boric acid, which reacts with the F, thereby destroying the complex and allowing hydrolysis. 

Aqueous solutions of acidic metal salts are usually inherently unstable and hydrolyze readily to oxides (the hydroxides of these metals tend to be relatively unstable), in some cases forming films. Such hydrolysis can be more readily controlled by adding boric acid to fluoro-complexes of the metal, e.g. ... 

Exercise 22-10 Why is nitration with ethanoyl nitrate accelerated by added fluoro-boric acid, HBF4, but retarded by added hydrochloric acid ... 

Benzoyl-1,2-dihydro-1-cyanoisoquinoline was treated with fluoro-boric acid in glacial acetic acid to give the Reissert salt 56 reactions of the latter with EPP, DMAD, and ethyl tetrolate were examined. With EPP, the initial bridged compound 58 was isolated as a moderately stable crystalline compound, and was the first example of an isolated... 

ESTERIFICATION Boric acid. Boron tri-fluoride ethcratc. Hcxamcthylphosphoric ttiamidc. lon-cxchange resins. Methyl f-butyl ether. Tricthyloxonium fluoro-borate. Trimethyl phosphite. 

When 2, 3, 5 -tri-0-acetyladenosin-8-amine is diazotized with sodium nitrite in 40% fluoro-boric acid at 20 °C, 2, 3, 5 -tri-0-acetyl-8-fluoroadenosine (3) is obtained in approximately 10% yield. 8-Fluoroinosine and adenin-8-ol are also obtained as byproducts. 

Liquid phase deposition (LPD) process is the formation of oxide thin films from an aqueous solution of a metal-fluoro complex which is slowly hydrolyzed by adding fluoride scavengers such as boric acid or aluminum metal [47], namely... 

Schiemann and related displacements. Addition of an ice-cold solution of fluoro-boric acid to a vigorously stirred solution of benzenediazonium chloride at 0° gives a yellowish crystalline precipitate of benzenediazonium fluoroborate, which is collected, washed with ice water, methanol, and ether, and dried. The solid is... 

Fluoropyridine, which is rapidly converted into Ar-(4-pyridyi)-4-pyridone in aqueous solution, has been prepared by diazotization of 4-aminopyri ne in fluoro-boric acid solution with sodium nitrite, followed by neutralization at — 20°C and distillation alternatively, diazotization may be achieved in anhydrous hydrofluoric acid followed by thermal decomposition of the diazonium fluoride at 50 °C with isolation of the 4-fluoropyridine with an organic solvent. The latter method has been applied to the preparation of 2,6-difluaropyridine from 2,6-diamino-pyridine. The 6-fluoro-derivatives of a large number of 3- and 5-nitro- and 3,5-... 

Cycloheptatriene does not react with Fe(CO)s to give the expected dicarbonyl complex 7i -C7H8Fe(CO)2, but forms instead a mixture of tricarbonyl complexes derived from cycloheptatriene and cyclohepta-1,3-diene (20, 35). This work, together with protonation and related reactions of the free double bond of 7r-C7HsFe(CO)3, have been summarized by Pettit and Emerson (118). More recently, Pettit and co-workers (101) have shown that (7-methoxycycloheptatriene)Fe(CO)3 is protonated by fluoro-boric acid with loss of methanol to give the ir-tropylium-iron tricarbonyl cation. 

Methylindole hydrogenated 5hrs. with PtOg in ethanol and aq. 42%-fluoro-boric acid at room temp, and atmospheric pressure 3-methylindoline. Y > 95%. F. e. and limitations s. A. Smith and J. H. P. Utley, Ghem. Gommun. 1965, 427. 

Flame Retardant n (1947) A material that reduces the tendency of plastics to burn. Flame retardants are usually incorporated as additives during compounding, but sometimes applied to surfaces of finished articles. Some plasticizers, particularly the phosphate esters and chlorinated paraffins, also serve as flame retardants. Inorganic flame retardants include antimony trioxide, hydrated alumina, monoammonium phosphate, dicyandiamide, zinc borate, boric acid, and ammonium sulfamate. Another group, called reactive-type flame retardants, includes bromine-containing polyols, Chlorendic acid and anhydride, tetrabromo- and tetrachlorophthalic anhydride, tetrabromo bisphenol A, diallyl chlorendate, and unsaturated phosphonated chlorophenols. A few neat resins, such as PVC and the fluoro- and chlorofluo-rocarbons, are flame-retardant (Elias, H (2003) An introduction to plastics. Wiley, New York Modem plastics encyclopedia. McGraw-Hill/Modem Plastics, New York, 1986 1990, 1992, 1993 editions). See Flammability. 

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