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Alkylation with isopropyl fluoride

O-Alkylation is also favored using more sterically hindered electrophiles such as secondary alkyl halides thus, alkylation of 2-pyridone with isopropyl iodide under mild conditions in the presence of cesium fluoride at room temperature leads to the formation of a mixture of N- and O-alkylated products in a 11 89 ratio <1995SL845>. [Pg.301]

Effects of Water in HF Catalyst. A number of investigators have pointed out that water has an important role in alkylation catalysts. Schmer-ling (1955) stated that the use of HF catalyst with one percent water produced a favorable result In propylene-isobutane alkylation, whereas, with a catalyst containing ten percent water, isopropyl fluoride was the principal product and no alkylate was formed. (Both reactions were at 25C.) Albright et al. (1972) found the water content of sulfuric acid to be "highly important" In affecting the quality and yield of butene-isobutane alkylate. They postulated that the water content of sulfuric acid controlled the level of ionization and hydride transfer rate In the catalyst phase. It appears that dissolved water affects HF alkylation catalyst similarly and also exerts further physical influence on the catalyst phase such as reducing viscosity. Interfacial tension, and isobutane solubility. [Pg.43]

If a C-substituted derivative of TOSMIC is used in the reaction, the product is a 1,4,5-trisubstitutcd imidazole. Such substituted isocyanidcs can be made either by dehydration of the iV-(a-tosylalkyl)formamide, or by alkylation of an appropriate isocyanide followed by reaction with tosyl fluoride. It is also possible to alkylate TOSMIC directly using phase transfer conditions 13], Such alkylations work best with primary alkyl halides (75-95%), with the isopropyl (40%), allyl (75%) and benzyl (80%) derivatives proving quite accessible. [Pg.121]

Tertiary C-H tonds show the highest reactivity. C-C bonds are generally more reactive than secondary or primary C-H bonds, leading to preferential nitrolysis of n-alkanes(cleavage nitratlcn) The nitronium ion, which is linear itself, does not seem to exercise excessive steric hindrance in the transition states of the reactions, where it is substantially bent (indicated also from its behavior in electrophilic aromatic substitutions). Side products of the nitrolysis are methyl, ethyl, and isopropyl fluoride (formed by the reaction of PFg with the cleaved alkylcarbenium ions) or secondary alkylation products, themselves capable of undergoing reaction with the nitronium salt. [Pg.37]

Reactions of ar>l or alkyl bis(siloxy)isopropyl ethers with tetrabutyl-ammoninm fluoride-mesyl fluoride reagent lead to replacement of one siloxy group by fluorine and dehydrosiloxylation, providing an efficient access to fluoroisopropenyl ethers, which are useful as specific building blocks in drug design The reactions proceed via the intermediate allyl methanesulfonates [30, 31] (equation 23)... [Pg.208]

Xenon difluoride reacts with alkyl iodides at room temperature to give organic derivatives of polyvalent iodine. When an excess of iodomcthane (7) is treated with xenon difluoride it produces a stable solution of methyliodine difluoride in quantitative yield, the use of hydrogen fluoride as a catalyst allows a substantial amount of product to be obtained, while isopropyl iodide decomposes under the action of the reagent.16-21... [Pg.221]

In experiments where the produced alkyl fluorides were volatile (ethyl, isopropyl), the BFj OEtj was placed into the reaction flask, and a small amount of the fiuoroformatc was added. The stirred mixture was warmed up if necessary until evolution of CO2 commenced and then maintained at that temperature while the remainder of the fluoroformate was added gradually over a few hours. When gas evolution had ceased, the system was swept out briefly with helium, and the soda lime tubes were weighed to determine the amount of produced COj. The alkyl fluoride collected in the cold trap was redistilled into another cold receiver. [Pg.713]

Exercise 5,6,6. When isopropylbenzene is alkylated by n-butylene in the presence of hydrogen fluoride the reaction scheme is A —> B — > C with = isopropylbenzene, B = isopropyl-sec-butylbenzene, C iso-propyldi-sec-butylbenzene. From the following data estimate and k. ... [Pg.104]

Perdeuteriated isopropyl, t-butyl, and t-pentyl fluorides were prepared from the corresponding deuteriated alkyl chlorides (bromides) by halogen exchange. The perdeuteriated alkyl fluorides were then used in the formation of the deuteriated carbonium ions under similar conditions as those for the protium complexes. The resonance spectra were obtained at 9 2 Mc/s and the data are summarized in Table 7 The data indicate good agreement with those of the resonance data. [Pg.317]


See other pages where Alkylation with isopropyl fluoride is mentioned: [Pg.567]    [Pg.62]    [Pg.221]    [Pg.365]    [Pg.371]    [Pg.37]    [Pg.726]    [Pg.60]    [Pg.82]    [Pg.167]    [Pg.265]    [Pg.70]    [Pg.337]    [Pg.97]    [Pg.237]    [Pg.333]    [Pg.316]    [Pg.634]    [Pg.643]    [Pg.710]    [Pg.766]    [Pg.991]    [Pg.60]    [Pg.60]    [Pg.746]    [Pg.761]    [Pg.762]    [Pg.785]    [Pg.786]    [Pg.1038]    [Pg.1240]    [Pg.214]    [Pg.255]    [Pg.114]   
See also in sourсe #XX -- [ Pg.60 , Pg.62 ]




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Alkyl fluorides

Fluoride alkylation

Isopropyl fluoride

With fluoride

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