METHOD OF PRODUCING SYMMETRIC METHYLPHENYL DISILOXANES AND HEXAPHENYL DISILOXANE BY DEHYDRO-CONDENSATION OF TRIORGANOSILANES Russian patent published in 2019 - IPC C07F7/08 C07F7/18 

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and technology of producing symmetric hexa-organodisiloxanes. Disclosed is a method of producing symmetric methylphenyl disiloxanes and hexaphenyl disiloxane of general formula [R¹_nR²_(3-n)Si]₂O, where R¹ – CH₃; R² – C₆H₅; n = 0÷2, by dehydrocondensation of individual triorosilanes of type R¹_nR²_(3-n)SiH, in the presence of a lower alcohol and a carboxylic acid in catalytic action of a strong mineral acid and a Spayer catalyst both in an aromatic solvent and in the absence of a solvent, wherein the process is carried out at stepwise heating of the reaction mass: at temperature of 40–50 °C for 1–3 h, at temperature of 97 °C for 1.5–2 hours with subsequent gradual increase during 1 hour of mixture temperature to 120 °C with simultaneous distillation of alcohol and its acetate, wherein the stripped alcohol and acetate are returned into the reaction mass cooled to room temperature, the platinum black is separated by filtration, then reaction mixture is neutralized with calcium carbonate, mixture is re-filtered and volatile products are removed from target product under vacuum of 50 mm Hg at temperature of up to 120 °C. Disiloxane yield is not less than 97 wt.%, purity is not less than 98 wt.%.

EFFECT: disclosed method is simple in implementation, does not require complex equipment, is carried out in one apparatus, on mono-raw material – triorganosilane, provides high output and purity of disiloxanes; disiloxanes obtained using said method have high stability of properties, which is preserved during prolonged storage.

1 cl, 3 ex