Patent GB-740991-A (GB)
Title: Improvements in and relating to hydrolyzable organosilylethynes
IPC: C07F7/12
Filed: 1953-03-11
Abstract: Organosilicon polymers are prepared by hydrolysing organo-silicon compounds of the general formula <FORM:0740991/IV(a)/1> wherein R and R1 represent hydrocarbon radicals free from olefinic or acetylenic unsaturation, and X represents a halogen, an acyloxy radical derived from a saturated aliphatic carboxylic acid or an alkoxy radical derived from a saturated aliphatic alcohol, e.g. to form a polymer containing the unit structure <FORM:0740991/IV(a)/2>ALSO:The invention comprises organo-silicon compounds of the general formula <FORM:0740991/IV(a)/1> wherein R and R1 represent hydrocarbon radicals free from olefinic or acetylenic unsaturation, and X represents a halogen, an acyloxy radical derived from a saturated aliphatic carboxylic acid or an alkoxy radical derived from a saturated aliphatic alcohol, and a process for the preparation thereof by reacting a Grignard reagent Y-Mg-C ­ C-Mg-Y, wherein Y represents a halogen, with a diorganodihalogenosilane in which the organo radicals are hydrocarbon radicals and, if necessary, reacting the product with a saturated aliphatic carboxylic acid or anhydride or a saturated aliphatic alcohol.  R and R1 may be the same or different and may represent alkyl radicals such as methyl, ethyl, propyl, isopropyl, hexyl and dodecyl radicals, cycloaliphatic radicals such as cyclopentyl and cyclohexyl radicals, aryl radicals such as phenyl, diphenyl and naphthyl radicals, alkaryl radicals such as tolyl, xylyl and ethylphenyl radicals, and aralkyl radicals such as benzyl, phenylethyl and phenylbutyl radicals.  Suitable diorganodihalogenosilane reactants are dimethyldichlorosilane, methylphenyldichlorosilane, diethyldibromosilane, methylethyldichlorosilane, methylbenzyldifluorosilane and an ethyltolyldichlorosilane.  X is preferably chlorine, bromine or fluorine, an acyloxy radical of the formula <FORM:0740991/IV(a)/2> wherein Z is a lower alkyl radical such as the methyl, ethyl, propyl, isopropyl and butyl radicals, or an alkoxy radical such as the methoxy, ethoxy, propoxy, isopropoxy and isobutoxy radicals. The Grignard reaction is preferably carried out with an excess of the Grignard reagent, and a catalyst such as a small quantity of powdered cuprous chloride may be used.  The reaction to form the acyloxy derivatives of the above general formula in which the acyloxy groups may be the same or different is preferably carried out with an excess of the acid anhydride, and a catalyst such as a solution of triethanolamine in the acid anhydride.  The reaction to form the alkoxy derivatives of the above general formula are advantageously carried out in the presence of a hydrogen halide acceptor, e.g. a tertiary amine such as pyridine.  In the examples, tetramethyldichlorodisilylethyne (which may be hydrolysed to tetramethylethynyldisilanediol), tetramethyldiacetoxydisilylethyne and tetramethyldiethoxydisilylethyne are prepared.  The following compounds are also obtainable:- dimethyldiphenyldichlorodisilylethyne, tetraethyldimethoxydisilylethyne and dimethyldiphenyldipropoxydisilylethyne.  The compounds of the above general formula can be hydrolysed to form diols.