Patent GB-790090-A (GB)
Title: Cyclic boron compounds
Inventor: CONKLIN GEORGE WILLARD
IPC: F02C7/266
Filed: 1956-03-02
Abstract: The invention comprises cyclic boron compounds having the general formula <FORM:0790090/IV (b)/1> wherein X is an oxygen or sulphur atom, R is an alkylene radical such that the ring contains 2 or 3 carbon atoms, and R1 and R11 are hydrogen atoms or organic radicals, preferably alkyl radicals, which may be linked together so as to form a heterocyclic ring with the nitrogen atom.  The preferred compounds are the 1,3,2-dioxaborolanes and 1,3,2-dioxaborinanes.  A list of representative examples is given.  The novel compounds may be prepared by reacting an amine of the formula HNR1R11 with a corresponding halo-borolane or halo-borinane, the halogen being preferably chlorine or bromine.  The reaction is preferably effected at a temperature below 25 DEG , e.g. 0 DEG  to 15 DEG  C., in the presence of an inert solvent such as ether or dioxane and a hydrogen halide acceptor.  The amine starting material will generally function as a hydrogen halide acceptor when at least two molar equivalents of amine per equivalent of halo compound are used.  The amines used may be aliphatic, aromatic, alicyclic or heterocyclic primary or secondary amines.  A list of suitable amines is given, the preferred amines having 1 or 2 alkyl groups, or an alkylene group, containing 1 to 20, preferably 1 to 10, carbon atoms, attached directly to the nitrogen atom.  The halo-borolane and haloborinane starting materials can be prepared by reacting a boron trihalide with a diol, a dithiol, or hydroxy mercaptan wherein the -XH groups (X is oxygen or sulphur) are attached to adjacent carbon atoms or to carbon atoms separated by only one carbon atom.  The reaction is generally carried out at a temperature of - 10 DEG  C. to 100 DEG  C. and in the presence of an inert solvent such as methylene chloride or bromide, or ethylene chloride or bromide.  The preferred diols are the alkylene glycols having 2 to 20 carbon atoms.  In examples: (1) boron trichloride is reacted with ethylene glycol to give 2-chloro-1,3,2-dioxaborolane which is reacted with dimethylamine to give 2-dimethylamino-1,3,2-dioxaborolane; (2) 4-methyl-2-chloro-1,3,2-dioxaborolane, obtained from boron trichloride and propylene glycol, is reacted with dimethylamine giving 2-dimethylamino-4-methyl-1,3,2-dioxaborolane; (3) 2-methylamino-4-methyl-1,3,2 - dioxaborolane and (4) 2 - pyrrolidyl - 4 - methyl-1,3,2-dioxaborolane are similarly obtained; (5) 2 - (N - methylanilino) - 1,3,2 - dioxaborolane is obtained from N-methylaniline and 2 - chloro - 1,3,2 - dioxaborolane; (6) 2 - chloro - 1,3,2 - dioxaborinane, obtained from boron trichloride and 1,3-propanediol, is reacted with di-isopropylamine to give 2-diisopropylamine - 1,3,2 - dioxaborinane; (7) 2-chloro-4-methyl - 1,3,2 - dioxaborinane, obtained from boron trichloride and 1,3-butanediol, is reacted with dicyclohexylamine to give 2-dicyclohexylamino - 4 - methyl - 1,3,2 - dioxaborinane; (8) 2 - chloro - 1,3,2 - dithiaborolane, obtained from boron trichloride and ethane dithiol, is reacted with dimethylamine to give 2-dimethylamino1,3,2-dithiaborolane. The novel compounds are suitable as additives for lubricating oils and liquid fuels, and are useful as insecticides, fungicides and antiseptics.ALSO:Cyclic boron compounds of the formula: <FORM:0790090/III/1> wherein X is an oxygen or sulphur atom, R is such an alkylene radical the ring contains 2 or 3 carbon atoms, and R1 and R11 are hydrogen atoms or organic radicals, which may be linked together so as to form a heterocyclic ring with the nitrogen atom, are added in minor proportions to lubricating oils.  The compounds may be added to both mineral and synthetic lubricating oils such as polymers of alkylene glycols and alkylene oxides, or organic esters, e.g. bis(2-ethylhexyl) sebacate.  The novel boron compounds may also be added in minor proportions to liquid fuels, e.g. motor fuels.  (For preparation of the cyclic boron compounds see Group IV (b).)