Amines fluorides

Fluoramine (Nitrogen Dihydrogen Fluoride, Amine Fluoride). FNH2, mw 35.62, N 39.32% a colorl gas, subl -77° and 760mm (Refs 3, ... 

Moreover, the formation of enoxy-silanes via silylation of ketones127 by means of N-methyl-N-TMS-acetamide (1 72) in presence of sodium trimethylsilanolate (173) was reported in 1969 and since then, the use of silylating reagents in presence of a catalyst has found wide appreciation and growing utilization as shown in recent papers128-132 (Scheme 27). Diacetyl (181) can be converted by trifluoromethylsul-fonic acid-TMS-ester (182) into 2,3-bis(trimethylsiloxy)-l, 3-butadiene (7treatment with ethyl TMS acetate (7 5)/tetrakis(n-butyl)amine fluoride l-trimethylsiloxy-2-methyl-styrene (i<56)130. Cyclohexanone reacts with the combination dimethyl-TMS-amine (18 7)/p-toluenesulfonic acid to 1-trimethylsiloxy-l-cyclohexene (iSS)131. Similarly, acetylacetone plus phenyl-triethylsilyl-sulfide (189) afford 2-triethylsiloxy-2-pentene-4-one (790)132. ... 

As Table 1 demonstrates, the SiY bond length and the Si pyramidalization increases with increasing basicity of dimers, that is in direction THF, ethyldimethyl amine, fluoride. 

Clinical data from several long-term studies in Europe have demonstrated the effectiveness of the use of a dentifrice containing organic amine fluorides. The amine fluorides also have strong plaque-reducing properties. However, although the amine fluorides may be more effective for caries reduction than other forms of fluoride, the FDA has not allowed these products to be extensively tested in this country. 

Only a few studies have been published with regard to the influence of fluoride treatment on pellicle formation and composition. Contrary results have been reported concerning in vitro salivary protein adsorption on fluoride-treated enamel (table 4). Treatment of pellicle-covered as well as bare enamel surfaces with amine fluoride causes a decrease in surface free energy [184, 185], However, fluoridation of the enamel surface with sodium fluoride does not significantly influence the amino acid composition of the pellicle layer adsorbed in vivo [186], In contrast, stannous fluoride treatment of enamel... 

D Bohrer, Z Hirschfield and 1 Gedalia, Fluoride uptake in vitro by interproximal enamel fiom dental floss impregnated with amine fluoride gel , J. Dentistry 1983 11 271-273. 

A well-formulated product will ensure a level of fluoride in the saliva above 0.02 ppm for several hours [18]. Fluoride ions are present in toothpaste formulations largely in the form of stannous fluoride (Snp2), sodium monofluorophosphate (NajPOsF), and sodium fluoride (NaF). But we can also find in the literature potassium fluoride, lithium fluoride, aluminum fluoride, zinc fluoride, acidic phosphate fluoride, ammonium fluoride, titanium tetrafluoride, and amine fluoride. 

In practice, the compounds that provide the flnoride ions are sodium fluoride, sodium monofluorophosphate (Na2FP03), and sometimes certain amine fluorides. 

A similar protocol was used to compare the effects of Listerine against an amine fluoride/stannous fluoride-containing mouthrinse (Meridol ) and a 0.1% chlorhexidine mouthrinse (Chlorhexamed ) in inhibiting the development of supragingival plaque. On day 5 of each treatment, the results from 23 volunteers were evaluated. In comparison with their placebos, the median plaque reductions were 12.2%, 23%, and 38.2% for the fluoride, essential oil, and chlorhexidine rinses, respectively. The latter two results were statistically significant (Riep et al., 1999). 

Boron trifluoride catalyst may be recovered by distillation, chemical reactions, or a combination of these methods. Ammonia or amines are frequently added to the spent catalyst to form stable coordination compounds that can be separated from the reaction products. Subsequent treatment with sulfuric acid releases boron trifluoride. An organic compound may be added that forms an adduct more stable than that formed by the desired product and boron trifluoride. In another procedure, a fluoride is added to the reaction products to precipitate the boron trifluoride which is then released by heating. Selective solvents may also be employed in recovery procedures (see Catalysts,regeneration). 

Ammonium fluorosulfate is produced from ammonium fluoride by reaction with sulfur trioxide, oleum, or potassium pyrosulfate, 1 2820 (48). Solutions of ammonium fluorosulfate show Htfle evidence of hydrolysis and the salt may be recrystallized from hot water. Ammonium fluorosulfate absorbs anhydrous ammonia to form a series of Hquid amines that contain 2.5—6 moles of ammonia per mole of salt (77). 

ECF is successfully used on a commercial scale to produce certain perfluoroacyl fluorides, perfluoroalkylsulfonyl fluorides, perfluoroalkyl ethers, and perfluoroalkylamines. The perfluoroacyl fluorides and perfluoroalkylsulfonyl fluorides can be hydrolyzed to form the corresponding acid and acid derivatives. Examples include perfluorooctanoyl fluoride [335-66-0] perfluorooctanoic acid [335-67-1] perfluorooctanesulfonyl fluoride [307-35-7] perfluorooctanesulfonic acid [763-23-1] and tris(perfluoro- -butyl)amine [311-89-7]. 

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). 

Carbonyl sulfonyl fluorides of the formula FC0(CF2) S02F have been prepared by electrochemical fluorination of hydrocarbon sultones (41,42). More commonly in a technology pioneered by Du Pont, perfluoroalkanecarbonyl sulfonyl fluorides are prepared by addition of SO to tetrafluoroethylene followed by isomerization with a tertiary amine such as triethylamine (43). 

Fluoroaromatics are produced on an industrial scale by diazotization of substituted anilines with sodium nitrite or other nitrosating agents in anhydrous hydrogen fluoride, followed by in situ decomposition (fluorodediazoniation) of the aryldiazonium fluoride (21). The decomposition temperature depends on the stabiHty of the diazonium fluoride (22,23). A significant development was the addition of pyridine (24), tertiary amines (25), and ammonium fluoride (or bifluoride) (26,27) to permit higher decomposition temperatures (>50° C) under atmospheric pressure with minimum hydrogen fluoride loss. 

Chloro-2,4,6-trifluoropyrimidine [697-83-6] has gained commercial importance for the production of fiber-reactive dyes (465,466). It can be manufactured by partial fluoriaation of 2,3,5,6-tetrachloropyrimidine [1780-40-1] with anhydrous hydrogen fluoride (autoclave or vapor phase) (467) or sodium fluoride (autoclave, 300°C) (468). 5-Chloro-2,4,6-trifluoropyrimidine is condensed with amine chromophores to provide the... 

Cyanuric fluoride is readily hydrolyzed to 2,4,6-thhydroxy-l,3,5-triaziae [108-80-5] (cyanuric acid). Cyanuric fluoride reacts faster with nucleophilic agents such as ammonia and amines than cyanuric chloride. 

General Reaction Chemistry of Sulfonic Acids. Sulfonic acids may be used to produce sulfonic acid esters, which are derived from epoxides, olefins, alkynes, aHenes, and ketenes, as shown in Figure 1 (10). Sulfonic acids may be converted to sulfonamides via reaction with an amine in the presence of phosphoms oxychloride [10025-87-3] POCl (H)- Because sulfonic acids are generally not converted directiy to sulfonamides, the reaction most likely involves a sulfonyl chloride intermediate. Phosphoms pentachlotide [10026-13-8] and phosphoms pentabromide [7789-69-7] can be used to convert sulfonic acids to the corresponding sulfonyl haUdes (12,13). The conversion may also be accompHshed by continuous electrolysis of thiols or disulfides in the presence of aqueous HCl [7647-01-0] (14) or by direct sulfonation with chlorosulfuric acid. Sulfonyl fluorides are typically prepared by direct sulfonation with fluorosulfutic acid [7789-21-17, or by reaction of the sulfonic acid or sulfonate with fluorosulfutic acid. Halogenation of sulfonic acids, which avoids production of a sulfonyl haUde, can be achieved under oxidative halogenation conditions (15). 

Purine, 6-bromo-9-/3-D-(2,3,5-tri-0-acetyl)ribofuranosyl-synthesis, 5, 598 Purine, 6-carboxy-reactions, 5, 549 Purine, 8-carboxy-reactions, 5, 549 Purine, 2-chloro-reactions, 5, 561 synthesis, 5, 597 Purine, 6-chloro-alkylation, 5, 529 glycosylation, 5, 529 oxidation, 5, 539 3-oxides reactions, 5, 554 synthesis, 5, 595 reactions, 5, 561, 595 with ammonia, 5, 562 with fluorides, 5, 563 with trimethylamine, 5, 562 9- -D-ribofuranoside synthesis, 5, 560 synthesis, 5, 597, 598 Purine, 8-chloro-amination, 5, 542 Purine, 6-chloro-8-ethoxy-synthesis, 5, 591 Purine, 6-chloro-9-ethyl-dipole moment, 5, 522 Purine, 6-chloro-2-fluoro-riboside... 

The method should not be used for the first member of a homologous series or for temperatures much above the normal boiling point (T 0.75). Errors for both hydrocarbons and nonhydrocarbons average 15 percent for a wide variety of compounds. Higher errors are noted for amines, diols, ethers, and fluorides. Table 2-398 gives AN and AB contributions for most common groups. Space prohibits examples for... 

H-Bond Acceptor (HBA) Acyl chlorides Acyl fluorides Hetero nitrogen aromatics Hetero oj gen aromatics Tertiary amides Tertiary amines Other nitriles Other nitros Isocyanates Peroxides Aldehydes Anhydrides Cyclo ketones Ahphatic ketones Esters Ethers Aromatic esters Aromatic nitriles Aromatic ethers Sulfones Sulfolanes... 

The range of nueleophiles whieh have been observed to partieipate in nueleophilie aromatie substitution is similar to that for S[, 2 reactions and includes alkoxides, phenoxides, sulftdes, fluoride ion, and amines. Substitutions by earbanions are somewhat less common. This may be because there are frequently complications resulting from eleetron-transfer proeesses with nitroaromatics. Solvent effects on nucleophilic aromatic substitutions are similar to those discussed for S 2 reactions. Dipolar... 

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