Patent GB-591632-A (GB)
Title: Synthesis of organic halogen compounds from a lower boiling tertiary compound and mono-olefinic compound both of which are halogenated
IPC: C07C17/275
Filed: 1944-11-15
Abstract: Organic halogen compounds are synthesized by reacting a saturated aliphatic compound, having a tertiary carbon atom and with or without one or more halogenated aliphatic carbon atoms, with a mono-olefinic halogen compound, containing at least one halogenated aliphatic carbon atom, in the presence of a metal halide alkylation catalyst, at a temperature at which an organic halogen compound having a greater number of carbon atoms than either starting compound is produced.  Isoparaffins may be reacted with mono-olefinic halides having the halogen attached to a carbon atom directly linked to an olefinic carbon atom.  Normal paraffins capable of isomerization to isoparaffins under the reaction conditions may be used.  Starting materials specified include isobutane, isopentane, isohexanes, 2,3-dimethyl butane, hydrogenated olefin polymers such as isooctane, and alkyl substituted cyclohexanes as well as tertiary alkyl chlorides or corresponding fluorides, bromides and iodides including cyclo-paraffinic compounds having a tertiary carbon atom.  The tertiary halide may contain a plurality of halogen atoms. Mono-olefinic halogen compounds include vinyl and allyl type halides and may contain substituents such as aromatic groups. Halogenated cyclohexanes and their homologues and substitution products are also specified.  Petroleum cracking fractions containing paraffins and olefins, e.g. butane-butene fractions, may be halogenated or hydrohalogenated to give a mixture of tertiary butyl halide, butenes and butanes which can be further halogenated as disclosed in Specification 542,086 to obtain a mixture of tertiary and unsaturated halides for use in the process.  Unreacted butanes may be isomerized and/or halogenated or dehydrogenated and the olefins halogenated for use in the process.  Catalysts specified are aluminium chloride and bromide, ferric chloride, titanium tetrachloride, antimony trichloride, stannous, stannic and bismuth chlorides, either alone or on carriers.  Alumina may be dipped in fused aluminium chloride and the excess drained off under pressure.  Complexes of metal halides with ketone, alkyl halide or hydrocarbons or double salts of aluminium and Group I metals may be used, and hydrogen halide added as activator.  At least 1.5 mols. of the tertiary saturated compound are fed per mol. of mono-olefinic halogen compound and high ratios may be maintained in the reactor by continuous recycling.  Liquid, gas or mixed phase reaction may be employed. Using aluminium chloride catalysts, temperatures below 50 DEG  C., for example -20 DEG  to +20 DEG  C., are preferred.  Ferric chloride is active at 0 DEG  C. and temperatures are generally below 100 DEG  C.  The amount of catalyst may be .01 to 1 mol. or more per mol. of unsaturated halide.  In examples: (1) an aluminium chloride-allyl chloride complex is made by adding allyl chloride and hydrogen chloride to aluminium chloride in pentane at 0 DEG  C.  This catalyst is mixed with tert.-butyl chloride and allyl chloride added dropwise at -20 DEG  C. 70 per cent of the product is 1,2-dichlor-4,4-dimethylpentane; (2) at 0 DEG  C. increased amounts of light ends and higher boiling products are obtained; (3) ferric chloride at 10 DEG  C. gives similar results; (4) titanium tetrachloride acts similarly at 24 DEG  C. followed by standing overnight at 20 DEG  C. before catalyst removal; (5) tert.-butyl chloride and methallyl chloride in a molar ratio of 3 : 1 react at -20 DEG  C. in presence of aluminium chloride-tert.-butyl chloride complex to yield mainly 1,2-dichlor-2,4,4-trimethylpentane; (6) vinyl chloride under the same conditions yields a dichlorhexane, apparently 1,1 - dichlor - 3,3 - dimethylbutane, propenyl chloride gives 1,1-dichlor-2,3,3-trimethylbutane and crotyl chloride 1,2-dichlor-3,4,4-trimethylpentane; (7) replacing tert.-butyl chloride by tert.-amyl chloride in (1) yields mainly 1,2-dichlor-4,4-dimethylhexane; (8) allyl chloride and isobutane are fed to a mixer fitted with a separator, the catalyst being aluminium chloride at -20 DEG  C., and the products fractionated to yield heptanes, and mono- and di-chlorheptanes among other products; (9) a series of runs are made as in (8) using varying molar ratios and temperatures of +20 DEG  and -20 DEG  C.; (10) vinyl chloride is slowly run into isobutane containing aluminium chloride in a batch reactor at 0 DEG  and 20 DEG  C. to give products containing 2,3-dimethylbutane and dichlorhexane; (11) 2-chlorbutene-2 and isobutane react similarly at temperatures between 19 DEG  and 70 DEG C.; (12) the same reactants are used in a continuous process at 50 DEG  C.; (13) b -chlorpropylene and isobutane react at -10 DEG  to -20 DEG  C. using aluminium chloride to give tert.-butyl chloride, hexanes, heptanes, and higher boiling chlorides; (14) 1,3-dichlorpropylene is used in place of b -chlorpropylene; (15) methallyl chloride and isobutane using aluminium chloride at -20 DEG C. yield octanes, mono- and di-chlor-octanes among the products, while isopentane similarly gives nonanes and chlornonanes.  The yield of individual products may be increased as, for example, by recycling the dichloride to increase monochloride or by use of lower temperatures and addition of naphthenes to reduce hydrocarbon formation.  The halides produced may be used to obtain the corresponding paraffins of high anti-knock rating, they may be hydrolysed to alcohols or converted to esters of mono- or poly-carboxylic acids, used as solvents or plasticisers, and the alcohols may be converted to ethers, acids, ketones or aldehydes. The polyhalides of 6-21 carbon atoms may also be hydrolysed to aldehydes or ketones by heating with water at 100 DEG  C. in the presence of lead monoxide and such aldehydes and ketones condensed to higher unsaturated ones or reduced or oxidized to alcohols or acids. Thus, 1 - chlor - 3,4 - dimethylpentane obtained from allyl chloride and isobutane is hydrolysed with caustic potash to give 3,4-dimethylpentanol-1. The polyhalide products may be reacted with isoparaffins to produce monohalides.  The halides are solvents and thinners for lacquers, synthetic resin base enamels and varnishes and may be used for extracting oils and gums from vegetable materials and for dry cleaning.  In a further example: (16) 1,2-dichlor-4,4-dimethylpentane is reacted with isobutane using the catalyst complex of (1) at 0 DEG  C. to give isopentane, tert.-butyl chloride, heptanes, octanes and monochlor-heptane. Specification 554,825 also is referred to.  The Specification as open to inspection under Sect. 91 comprises the reaction of tertiary saturated aliphatic halides with mono-olefinic compounds generally, for example olefins, cyclo-olefins and their substitution products.  Additional catalysts specified are hydrogen halides such as hydrogen fluoride.  Examples describe the reaction of tert.-butyl chloride with propylene, ethylene, butene-2, cetene and isobutene, of 2 - chlor - 2,4,4 - trimethylpentane with ethylene, tert.-butyl bromide with propylene, and tert.-amyl chloride with trimethylethylene, the catalysts being antimony, aluminium, and ferric chlorides, and aluminium bromide. The use of poly-olefinic or acetylenic compounds in the reaction is also referred to.  This subject-matter does not appear in the Specification as accepted.