Boron chloride hydrogen fluoride

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Two structures are possible for the interaction of aromatic hydrocarbons with acids.270 In the a-structures a covalent bond is established between the acidic reagent and a particular carbon atom of the benzene ring. The a-structures are essentially classical carbonium ions. In the -structures a non-classical bond is established, not to any particular atom, but to the -electron cloud in general. It is quite likely that both types of structure are represented by actual examples. Thus m-xylene interacts more strongly with hydrogen chloride than does o-xylene, but the difference between the two hydrocarbons is much more pronounced when their interactions with a boron trifluoride-hydrogen fluoride mixture are compared. This is readily understandable... 

Alkyl halides are common alkylating agents in this reaction. Benzene is converted to toluene at atmospheric pressure by methyl chloride in the presence of aluminum chloride. Nitroparaffins have been used as solvents for the aluminum chloride catalyst. An amalgamated aluminum Catalyst is more effective than aluminum chloride in certain alkylations by alkyl chlorides. Boron trifluoride must be accompanied by water, alcohol, or some other polar compound in order to be effective in similar alkylations. Hydrogen chloride, hydrogen fluoride, ferric chloride, and beryllium chloride also have been used as catalysts. 

ACIDS, INORGANIC Boric acid. Chloro-Iridic acid. Hydrobtomic acid. Hydrochloric acid. Hydrogen bromide. Hydrogen chloride. Hydrogen fluoride. Hydrogen fluoride-Boron trifluoride. ion-exchange resins. Nitric acid. Periodic acid. Phosphoric acid. Folyphosphoric acid. Sulfuric acid. 

Friedel-Craets reaction Aluminum chloride. Benzenesulfonic anhydride. Boron trifluoride. 7-Butyrolactone. Catechol dichloromethylene ether. Chloroform (solvent). Chloromethyl methyl ether. 1,1-Didilorodimethyl ether. 2,4-Dinitrobenzenesulfenyl chloride. Hydrogen fluoride. Iodine. Folyphosphoric add. Sodium aluminum chloride. Stannic chloride. Sulfur. Sulfur monochloride. Titanium tetrachloride. Trichloramine. Zirconium tetrachloride. Friedel-Craets type reactions Dimethylacetamide. lodosobenzene. 

Other catalysts which may be used in the Friedel - Crafts alkylation reaction include ferric chloride, antimony pentachloride, zirconium tetrachloride, boron trifluoride, zinc chloride and hydrogen fluoride but these are generally not so effective in academic laboratories. The alkylating agents include alkyl halides, alcohols and olefines. 

Nitronium tetrafluoroborate has been prepared by interaction of nitric acid, hydrogen fluoride, and boron fluoride in nitromethane.5 However, mixtures of nitric acid and nitromethane are extremely explosive.6,7 The present modification of the procedure, in which the medium is methylene chloride instead of nitromethane, was developed to avoid this hazard. It has not been published before. 

Hydrazoic acid reaction with cyclobu-tanecarboxyhc acid, 47, 28 Hydrogenation of t butylazidoacetate to glycme ( butyl ester, 46,47 Hydrogen bromide 46, 43 reaction with y butyrolactone, 46, 43 Hydrogen fluoride anhydrous, precautions in use of, 46, 3 in preparation of mtromum tetra-fluoroborate 47, 57 reaction with benzoyl chloride, 46,4 with boron tnfluonde in conversion of p cymene to m cymene, 47, 40 in bromofluorination of 1 heptene, 46, 11... 

The polymerization of olefins in the presence of halides such as aluminum chloride and boron fluoride but in the absence of hydrogen halide promoter may also be described in terms of the complex carbonium ion formed by addition of the metal halide (without hydrogen chloride or hydrogen fluoride) to the olefin (cf. p. 28). These carbonium ions are apparently more stable than those of the purely hydrocarbon type the reaction resulting in their formation is less readily reversed than is that of the addition of a proton to an olefin (Whitmore, 18). Polymerization in the presence of such a complex catalyst, may be indicated as follows (cf. Hunter and Yohe, 17) ... 

The use of additional substances to increase the activity of a catalyst is a well known phenomenon. Hydrogen chloride or traces of water are known to promote aluminum chloride catalyzed reactions. In the same way the reaction of isoparaffins with olefins has been shown to be catalyzed by boron trifluoride in the presence of nickel powder and with water as the promoter (Ipatieff and Grosse, 76). Hydrogen fluoride can take the place of the water and thus serve as the promoter. 

No compound of boron with hydrogen has been obtained but the chloride, bromide, and fluoride are known. 

The addition of hydrogen fluoride to vinyl chloride (19) in the gas phase with activated carbon and boron trifluoride gives l-chforo-l-fluoroethane (90% yield).53... 

These products are thermally stable at room temperature but decompose at elevated temperatures by ehmination of CF2 The reaction with hydrogen fluoride is different from that with hydrogen chloride and hydrogen bromide Presumably this difference is derived from the strength of the boron-fluonne bond [108] (equation 86)... 

The reactivity of halogenated alkenes in the electrophilic hydrofluorination reaction decreases with an increasing number of halogen atoms. Thus polyhaloalkenes are rather resistant to the electrophilic addition of hydrogen fluoride.Therefore, the hydrofluorination needs catalysis, with boron trifluoride(Table 6), tantalum(V) fluoride (Table 5), antimony(V) chloride, niobium(V) fluoride,titanium(IV)chloride or molybdenum(V) chloride. ... 

Aluminum chloride and hydrogen fluoride have comparable effects on the coals. The addition of boron trlfluorlde to the hydrogen fluoride has no significant Influence on the extract-ability of the coals. After we ascertained the Influence of the catalyst system on the extractablllty of the coals, alkylation... 

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