CS217934B1 - Benzyldiphenylsilanol and its preparation - Google Patents

Abstract

The invention addresses the preparation of one of the components for the production of high-performance catalysts for the low-pressure polymerization of α-olefins, especially ethylene. The subject of the invention is a hitherto unknown benzyldiphenylsilanol of the structural formula loj (o)-ch2 -Si—Cl o and a method for their preparation by controlled hydrolysis of benzyldiphenylhalosilane.

Description

The invention relates to a previously undescribed chemical compound of benzyldiphenylsilanol of the general formula (ΟγΗγΧΟ^Η^Ϊ^ίΟΗ) and a method for its preparation.

Compounds of the general formula R^RgRjSiX, ^R ,> ^{6 K} 3 ? ^are aromatic, aliphatic or elicyclic organic substituents and X is an active, easily interchangeable inorganic substituent such as a halogen atom, hydroxyl group, etc., have recently gained considerable importance as intermediates in the synthesis of organosilicon esters of chromic acid, which are used as basic components of highly active systems catalyzing the low-pressure polymerization of α-olefins, especially ethylene. In addition to perphenylated silyl esters (R,“RgsR^CgHj) of chromic acid, analogous esters with one phenyl substituent replaced by an alkyl group have recently begun to be used. One of them is bis(benzyldiphenylsilyl)ester of chromic acid, the synthesis of which requires suitable compounds containing a benzyldiphenylsilyl group as starting components. The most preferred compound, as yet undescribed, appears to be benzyldiphenylsilanol.

The subject of the invention is the compound benzyldiphenylsilanol of the general formula (CyH?)(CgH^JgSiOH of the structural formula

Si—OH

Furthermore, the invention relates to the synthesis of benzyldiphenylsilanol by hydrolysis of benzyldiphenylhalosilane of the structural formula

where X represents chlorine, bromine or iodine, by the action of aqueous solutions of potassium or sodium bicarbonate in a heterogeneous solvent system consisting of an organic solvent and water. Ethers, aromatic hydrocarbons or halogenated hydrocarbon derivatives can be used as organic solvents, preferably diethyl ether, benzene or dichloromethane. The reaction proceeds according to the equation (C-fHyXCgH^SiX + HCO~ -* (C ₇ H ₇ )(CgH ₅ ) ₂ SiOH + X ^- + C0 ₂

The hydrolysis is carried out at room temperature with a slight excess of the alkaline reacting component and is completed by heating the more volatile component of the solvent system to the boiling point for one hour. The product is isolated by separating the solvent layers, drying the organic layer and evaporating the solvent in vacuo. The residue solidifies crystalline. The yield exceeds 75% of theory.

The synthesis of the preparation is demonstrated by the following examples:

Example

A solution of 30.9 g (0.1 mol) of benzyldiphenylchlorosilane in 120 ml of diethyl ether is added to a mixture of 50 ml of diethyl ether and a solution of 15 g (0.15 mol) of potassium bicarbonate over 1 hour with stirring. The mixture is then heated to the boiling point of the organic solvent for another hour with constant stirring. After cooling, the layers are separated, the ethereal layer is washed four times with 50 ml of water and dried over anhydrous sodium sulfate. The filtered solution is freed from the solvent by distillation under vacuum and the remaining clear, colorless oily product solidifies crystallinely on standing.

23 g of white crystalline product are obtained, which represents 79.2% of theory.

Example 2

Over the course of one hour, a solution of 52.5 g (0.17 mol) of benzyldiphenylchlorosilane in 200 ml of dichloromethane is added to a mixture of 100 ml of dichloromethane and a solution of 21 g (0.25 mol) of sodium hydrogen carbonate in 200 ml of water. After mixing, the mixture is heated to gentle reflux for another 1 hour. After cooling, separation of the layers and drying of the dichloromethane layer, the solvent is distilled off under vacuum. The remaining clear, colorless oily product solidifies crystallinely on standing. 37.5 g of white crystalline product (76% of theory) is obtained.

The same preparation was obtained in yields of 77 to 83% by hydrolysis of benzyldiphenylbromosilane and benzyldiphenyliodosilane according to Examples 1.

The same preparation was obtained in yields of 75 to 79% by hydrolysis in the presence of potassium or sodium bicarbonate according to Example 1 in environments where the organic component of the system was benzene, chloroform and carbon tetrachloride.

The prepared preparations were recrystallized from solutions in saturated aliphatic C11-C8 hydrocarbons, preferably from n-pentane, by cooling the saturated solutions.

Product properties and identification:

The product forms solid, colorless crystals in air, readily soluble in diethyl ether, benzene, chloroform, dichloromethane, ethanol, acetone, less soluble in cold aliphatic hydrocarbons such as pentane, hexane.

Melting point: 49 to 52 °C

Table 1

Elemental analysis results for ^c i ₉ h ₁₈ sío

Element content % C H You active H calculated 78.57 6.25 9.67 0.347 found 78.28 6.08 9.72 0.353

Infrared spectrum

The wavenumbers and assignments of the absorption bands are given in Table II. The infrared spectrum of benzyldiphenylsilanol was obtained [on a Specord IR-75 instrument] in the range 400 to 4,000 cm ^- ' in a KBr cuvette 0.26 mm (solution in GCl^, CSg). The interpretation of the bands was carried out on the basis of vibrational analysis and comparison with the spectra of similar compounds, mainly triphenylsilanol, triphenylchlorosilane. The presence of phenyl groups, methylene and Si-OH vibrations can be clearly identified in the spectrum.

' ³ C and ²⁹ Si NMR spectrum.

^{The J} C NMR spectrum of the compound was measured at a frequency of 25.047 MHz, the Si NMR spectrum at a frequency of 19.788 MHz. A 25# solution of the substance in deuteriochloroform with tetramethylsilane as an internal standard was used for the measurements. - 0; ů( ²⁹ Si)^g = 0]. The measurements were carried out at a temperature of 25 °C. The chemical shift values are expressed in ppm (positive values indicate a shift to a lower field).

Table II

Infrared spectrum of benzyldiphenylsilanol

160 190 watts

480

570

belt (cm ^-1 ) assignment abs. waist (cm ^- ) assignment sh X-sens. Ph 1,768 vw with X-sens. Ph 1,816 vw comb. and harm. vs. X-sens. Ph 1,883 years _γ (CH)Ph with υ (Si-C) 1955 VW w and (CCC)Ph w and (CCC)Pfi 2,892 watts υ s (CHg) vs. respiratory effort Ph 2,925 watts u as (CHg) vs. γ (C-H)Ph with γ (C-H)Ph 3,002 meters vs-b υ (Si-O) 3,028 sec m _γ (CH)Ph 3,055 seconds ,, (C-H)Ph m def. ring Ph 3,072 sec ra β (C-H)Ph 3,083 meters Λ m β (C-H)Ph 3,440 W-b v(Si-OH-O) vs. X-senz.Ph 3,550 w-b 1 vs. X-senz.Ph 3,675 seconds _υ (Si-OH) with 5 (Si-CH ₂ )

β (C-H)Ph υ (Ph-CHg)

Ph -phenyl

X-sens. - strip sensitive to substances

207 sec

262 vw β (C-H)Ph 302 w β (C-H)Ph 334 vw υ (C-C)Ph 431 vs. υ (C-C)Ph 452 with δ ( _CH2 ) 495 vs υ (C-C)Ph 590 m υ (C-C)Ph 600 m υ (C-C)Ph.

Band intensities vs - very strong s - strong m - medium w - weak vw - very weak sh - fold kur spectrum:

δ(Ο,) = 135.1 δ(0 ₂ ) = 134.3 S<C ₃ ) = 127.6 S(C ₄ ) = 129.7

X e(C _? ) = 25.1 8(Cg) = 137.4 w(C ₇ ) = 128.8 8(Cg) » 128.0 s(C ₉ ) = 124.3

2^Si NMR spectrum:

8<Si) = -8.8

29

C and Si NMR spectrum unambiguously confirms the identity and predicted structure of the compound, as well as the high degree of purity of the preparation.

Claims (3)

A compound of the formula (C CH H H) (CgH ^ gSiOH of the structural formula) CH ₂ —Si — OH 2. A process for preparing a compound according to claim 1, wherein the benzyldifenylhalogensilan structural formula CH ₂ -Si-X where X is chlorine, bromine or iodine, hydrolyzed with aqueous potassium bicarbonate or sodium hydroxide in a heterogeneous solvent system comprising an organic solvent and water. 3. Process according to claim 2, characterized in that ethers, aromatic hydrocarbons or halogenated derivatives of aliphatic hydrocarbons, preferably diethyl ether, benzene or dichloromethane, are used as organic solvents.