Hexafluoro

If triphenylmethyl chloride in ether is treated with sodium, a yellow colour is produced due to the presence of the anionic spiecies PhsC". Alternatively, if triphenylmethyl chloride is treated with silver perchlorate in a solvent such as THF, the triphenylmethyl cation is obtained. More conveniently, triphenylmethyl salts, PhsC X", can be obtained as orange-red crystalline solids from the action of the appropriate strong acid on triphenylcarbinol in ethanoic or propanoic anhydride solution. The perchlorate, fluoroborate and hexafluoro-phosphate salts are most commonly used for hydride ion abstraction from organic compounds (e.g. cycloheptatriene gives tropylium salts). The salts are rather easily hydrolysed to triphenylcarbinol. 

Fluoroe thane 1 1 Difluoroethane 111 Tnfluoroethane Hexafluoroe thane... 

FLUORINECOMPOUNDS,ORGANIC - PERFLUORINATED ETHYLENE-PROPYLENE COPOLYTffiRS] (Vol 11) l,l,l,3,3,3-Hexafluoro-2-propyl fluromethyl ether [28523-86-6]... 

The polymers dissolve in l,l,l,3,3,3-hexafluoro-2-propanol [920-66-1/, hot phenols, and /V, /V- dim ethyl form am i de [68-12-2] near its boiling point. The excellent solvent resistance notwithstanding, solvents suitable for measurement of intrinsic viscosity, useflil for estimation of molecular weight, are known (13,15). 

Flame-Retardant Treatments For Wool. Although wool is regarded as a naturally flame-resistant fiber, for certain appHcations, such as use in aircraft, it is necessary to meet more stringent requirements. The Zirpro process, developed for this purpose (122,123), is based on the exhaustion of negatively charged zirconium and titanium complexes on wool fiber under acidic conditions. Specific agents used for this purpose are potassium hexafluoro zirconate [16923-95-8] [16923-95-8] K ZrF, and potassium hexafluoro titanate [16919-27-0], K TiF. Various modifications of this process have been... 

All three fluorophosphoric acids are commercially available. The mono- and difluoro acids can be made as anhydrous or hydrated Hquids. Commercial hexafluorophosphoric acid is an aqueous solution. Anhydrous hexafluorophosphoric acid maybe prepared at reduced temperatures and pressures but it dissociates rapidly into PF and HF at 25°C (56). When diluted with water all the fluorophosphoric acids hydrolyze producing orthophosphoric acid. The hexafluoro acid is the most stable of the three fluorophosphoric acids. 

Hexafluoro-2,5-dihydrofuran [24849-02-3] is distilled into sulfur trioxide [7446-11-9] at 25°C. Addition of trimethyl borate [121-43-7] initiates a reaction which upon heating and distillation leads to a 53% yield of difluoromaleic anhydride. Dichloromaleic anhydride [1122-17-4] can be prepared with 92% selectivity by oxidation of hexachloro-1,3-butadiene with SO in the presence of iodine-containing molecules (65). Passing vaporized... 

Sevoflurane. Sevoflurane, l,l,l,3,3,3-hexafluoro-2-propyl fluromethyl ether [28523-86-6] is nonpungent, suggesting use in induction of anesthesia. The blood/gas partition coefficient is less than other marketed products (Table 1) yet similar to nitrous oxide, suggesting fast onset and recovery. In animal studies, recovery was faster for sevoflurane than for isoflurane, enflurane, or halothane (76). Sevoflurane is stable to light, oxygen, and metals (28). However, the agent does degrade in soda lime (77). 

Pyrazoles are formed when the diazo compounds react with alkynes or with functionalized alkenes, viz. the enols of /3-diketones. Pyrazolenines (353 Section 4.04.2.2.1) are isolated from disubstituted diazomethanes. Many pyrazoles, difficult to obtain by other methods, have been prepared by this procedure, for example 3-cyanopyrazole (616) is obtained from cyanoacetylene and diazomethane (7iJCS(C)2i47), 3,4,5-tris(trifiuoromethyl)pyrazole (617) from trifluorodiazoethane and hexafluoro-2-butyne (8lAHC(28)l), and 4-phenyl-3-triflylpyrazole (618 R =H) from phenyltriflylacetylene and diazomethane (82MI40402). An excess of diazomethane causes iV-methylation of the pyrazole (618 R = H) and the two isomers (618 R = Me) and (619) are formed in a ratio of 1 1. 

However, the thermolysis of diacylfuroxans (429) yielded two types of nitrile Af-oxides. An uncrowded diacylfuroxan such as (429a) rearranged to the a- acyloximino nitrile A-oxide (430) the diacylfuroxan with bulky substituents such as in (429b) gave rise to the half molecule acyl nitrile Af-oxide (431). Both types of nitrile Af-oxides (431) and (430) have been trapped with DMAD and hexafluoro-2-butyne to give isoxazoles in good yield. These reactions are shown in Scheme 97. 

Ferracyclopent-3-ene, hexafluoro-synthesis, 1, 669 Ferracyclopent-3-ene-2,5-dione synthesis, 1, 669... 

Hexafluoro-2-phenyl-2-propanol may be recovered from mother liquors, recovered solvent, and the KBr salt cake by extracting the mixture with aqueous base. Neutralization of the aqueous phase gives the alcohol (13-23 g.) which is purified by distillation. 

This dialkoxydiphenylsulfurane has been prepared by the reaction of diphenyl sulfide, 2,2,2-trifluoro-l-phenyl-l-(trifluoromethyl)ethyl hypochlorite, and potassium l,l,l,3,3,3-hexafluoro-2-phenyl-2-propanolate and by the reaction of diphenyl sulfide with 1 equivalent of chlorine and 2 equivalents of potassium 1,1,1,3,3,3-hexafluoro-2-phenyl-2-propanolate in diethyl ether. ... 

E. Tricarbonyl[ 1,2,3,4,5-tj) -2-methoxy-2,4-cydohexadien-1 - Z]-iron(l +) Hexafliu)rophosphate(l —). To the aqueous layer from Part D is added with swirling 7.1 g. (0.044 mole) of ammonium hexafluoro-phosphate (Note 23) in 30 ml. water. After 30 minutes, the light-yellow product is filtered, washed with water, and air dried the yield is about 9-10 g. (35-447o) (Notes 19, 24). 

Iron pentacarbonyl and l-methoxy-l,4-cyclohexadiene react as shown by Birch and oo-workera, but in dibutyl ether this solvent has been found superior. The tricarbonyl(methoxy-l,3-cyclohexadiene)iron isomers undergo hydride abstraction with triphenylmethyl tetrafluoro-borate to form the dienyl salt mixture of which the 1-methoxy isomer is hydrolyzed by water to the cyclohexadienone complex. The 2-methoxy isomer can be recovered by precipitation as the hexafluoro-phosphate salt. By this method the 3-methyl-substituted dienone complex has also been prepared from l-methoxy-3-methylbenzene. The use of the conjugated 1-methoxy-1,3-cyclohexadiene in Part B led to no increase in yield or rate and resulted chiefly in another product of higher molecular weight. An alternative procedure for the dienone is to react tricarbonyl(l,4-dimethoxycyclohexadiene)iron with sulfuric acid. ... 

The fluororubbers also form an important class of speciality elastomers and although the market is dominated by the vinylidene fluoride-hexafluoro-propylene copolymers a wide range of materials has been produced over the past 40 years. 

Furthermore, the stereochemistry of the product 1 changes as the solvent is changed. In aqueous dioxane, the reaction proceeds with complete inversion, but in 1,1,1,3,3,3 hexafluoro-2-propanol with 100% retention. In acetic acid, the reaction occurs mainly with inversion (83%), but in formic acid the amount of retention (40%) is comparable to the amount of inversion (60%). Discuss these results, particularly with respect to the change of product composition and stereochemistry as a function of solvent. 

Hexafluoro-2-butyne adds to the 14,16-diene-20-one (62) at 120° to form the Diels-Alder product, for which structure (63) is proposed. ... 

Hexafluoro-2-butyne readily undergoes anionic oligomerization in the presence of fluoride ion 24 ], but the intermediate vinylic carbamon can be trapped by highly electrophilic fluormated heterocycles [249] (equation 52)... 

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