Patent GB-851169-A (GB)
Title: Method of producing boron hydrides or boron hydrides containing substituent organic radicals
IPC: C07F5/00
Filed: 1958-03-18
Abstract: Boron hydrides, e.g. diborane or pentaborane or boron hydrides containing substituent organic radicals are prepared by reacting a boron halide with an alkali metal hydride, in the presence of a di-, or tri-, alkylamine and an activator for the metal hydride, in an inert organic liquid to form a di-, or tri-, alkylamine-borine complex, which is then reacted with further boron halide to form the hydride product.  The reaction may be two immediately succeeding stages, or separate stages, in which case the alkali metal halide and activator may be removed from the reaction mixture after the first stage.  The temperature is 50 DEG -120 DEG  C.  Different halides may be used in the two stages.  The boron halide may be a boronhalogen compound which may contain 1 or 2 organic radicals, e.g. methyl or butyl, phenyl, tolyl, aroxy, or alkoxy.  The boron halides may be used in the form of addition compounds with organic N2 or O2 compounds, but the examples refer only to the use of BCl3, BF3, and BF3-diethyl etherate, and of BCl3 in the first stage and BF3 in the second stage.  All examples refer to tri-ethyl amine, as the amine reactant, but trimethyl-, propyl-, and isopropyl-amines are also referred to.  The activator, which may be present in amount up to 30% mol., may be an organoborine, containing methyl-, ethyl-, propyl-, butyl-, hexyl-, methoxy-, ethoxy-, butoxy-, hexoxy-, or phenyl-radicals, and which may contain 1 or 2 H, an ester of boric, or alkylborinic, or boronic acids, or an organo-metallic compound, or metal alcoholate which reacts with the boron halide to form an organo-borine, e.g. alkyl-, or alkoxy-, compounds of Li, Na, Mg, Ca, Zn, or Al. Examples refer to B(C2H5)3.  Organic liquids should have a boiling point 50 DEG -450 DEG C. and may be hexane, heptane, octane, benzene, toluene, xylene, cyclohexane, methyl cyclohexane, methyl naphthalene, triethyl silane, or mineral oil.  In the second stage of the reaction less than the stoichiometric amount of boron halide may be used, when a mixture of boron halide-amine complex and amine-borine complex is obtained, which mixture reacts more readily with alkali metal hydride, in the presence of the activator to form, from the halide-amine complex, amine-borine complex which may be reused.  Specification 830,768 is referred to.ALSO:Boron hydrides, e.g. diborane or pentaborane or boron hydrides containing substituent organic radicals are prepared by reacting a boron halide with an alkali metal hydride, in the presence of a di-, or tri-, alkylamine and an activator for the metal hydride, in an inert organic liquid to form a di-, or tri-, alkylamine-borine complex, which is then reacted with further boron halide to form the hydride product.  The reaction may be two immediately succeeding stages, or separate stages, in which case the alkali metal halide and activator may be removed from the reaction mixture after the first stage.  The temperature is 50-120 DEG C.  Different halides may be used in the two stages.  The boron halide may be a boron-halogen compound which may contain 1 or 2 organic radicals, e.g. methyl to butyl, phenyl, tolyl, aroxy, or alkoxy.  The boron halides may be used in the form of addition compounds with organic N2 or O2 compounds, but the examples refer only to the use of BCl3, BF3 and BF3-diethyl etherate, and of BCl3 in the first stage and BF3 in the second stage.  All examples refer to triethyl amine, as the amine reactant, but tri-, methyl-, propyl-, and isopropyl-amines are also referred to.  The activator, which may be present in amount up to 30 mol. %, may be an organo-borine, containing methyl-, ethyl-, propyl-, butyl-, hexyl-methoxy-, ethoxy-, butoxy-, hexoxy-, or phenyl-radicals, and which may contain 1 or 2 H, an ester of boric, or alkyl-borinic, or boronic acids, or an organo-metallic compound, or metal alcoholate which reacts with the boron halide to form an p  organo-borine, e.g. alkyl-, or alkoxy-, compounds of Li, Na, Mg, Ca, Zn, or Al.  Examples refer to B(C2H5)3. Organic liquids should have a boiling point 50-450 DEG C. and may be hexane, heptane, octane, benzene, toluene, xylene, cyclohexane, methyl cyclohexane, methyl naphthalene, triethyl silane, or mineral oil.  In the second stage of the reaction less than the stoichiometric amount of boron halide may be used, when a mixture of boron halide-amine complex and amine-borine complex is obtained, which mixture reacts more readily with alkali metal hydride, in the presence of the activator to form, from the halide-amine complex, amine-borine complex which may be re-used. Specification 830,768 is referred to.