DD269387A1 - PROCESS FOR PREPARING TETRAKIS (DIALKYLAMIDO) TITANIUM AND -ZIRCONIUM - Google Patents

Abstract

The invention relates to a novel process for the preparation of tetrakis (dialkylamido) titanium and zirconium, M (NRR) 4 (MTi, Zr; R, RC1-C4-alkyl group), which can be used as catalysts in homogeneous catalysis and as valuable Synthesis building blocks are of importance. Known processes require as starting material lithium or lithium organyls. According to the invention, the object is achieved by reacting dialkylamidomagnesium halides with titanium or zirconium halides or their tetrahydrofuran adducts with the addition of dioxane for the complete removal of the magnesium halides.

Description

Field of application of the invention

Oils invention relates to a novel process for the preparation of tetrakl (dlalkylamldo) tltanlum and zirconium from readily available starting materials, Dialkylamidometallverbindungen can be used as catalysts for the amnnomethylation of olefins and for the polymerization of olefins and Dloleflnen. They continue to be valuable intermediates in synthetic chemistry.

Characteristic of the well-known solutions

It is known that tetrakis (dialkylamido) titanium and zirconium can be prepared by reacting lithium dialkylamides prepared from secondary amines and butyllithium (D.C. BRAOl EY and I. M. THOMAS, J. Chem. Soc. (1960) 3857). The titanium compound is also accessible by reacting secondary amine with lithium and styrene and titanium tetrachloride (MT REETZ, R. URZ and T. SCHUSTER, Synthesis (1983) 540), but with only one product containing up to 4% impurities Both ancestors require the use of relatively expensive lithium or lithuanium organyls.

Object of the invention

The aim of the invention is to produce tetrakis (dialkylamido) titanium and zirconium without using expensive lithium or organyllithium compounds as starting materials.

Explanation of the essence of the invention

The task of synthesizing Totrakis (dialkylamido) titanium and zirconium without the use of expensive lithium or organyllithium compounds is inventively achieved by reacting alkylgrignard compounds with the corresponding diricylamine RR'NH (R, R '"C, - to C) in an ethereal solvent _4- alkyl group) is converted into a solution of dialkylaminedomagnesium halide, d ', in excess (molar ratio 4.5-8: 1, preferably 6-7: 1) to a suspension of titanium or Zirkoniumtetrahalogenld or their tetrahydrofuran adducts are added dropwise in ethers or hydrocarbons (preferred benzene / toluene). After filtering off the precipitated maynesium salts, the reaction is completed and the magnesium halides are completely removed with dioxane. The precipitated Magneniumhalogenid-dioxane adducts are filtered off and wins the use after distilling off the solvent by fractional distillation in vacuo. The compounds are halogen-free and show no further signals in the C-NMR spectrum except for the signals of the carbon atoms of the alkyl groups.

exemplary

example 1

To a solution of 1.5 mol of ethylmagnesium bromide in 500 ml of ether, prepared by reacting 168.9 g (1.55 mol) of ethyl bromide with 37.7 g (1.55 mol) of magnesium, is added dropwise at ⁰ ° C. with stirring 109.7 g (1, 5mol) diethylamine in kX) ml of ether slowly. After completion of the reaction, recognizable by the termination of the evolution of ethane, is allowed to warm to room temperature and the reaction solution filtered through glass wool.

This solution is added dropwise while stirring at 0 ° C to 52.0 g (0.22 mol) of zirconium tetrachloride in 250ml benzene. After complete addition, the mixture is warmed slowly to room temperature and heated for 2 h at reflux. After cooling to room temperature, the precipitate is filtered off and washed with about 100 ml of ether. The combined filtrates are slowly covered with 150 ml of dioxane and the resulting precipitate is filtered off again. The solvents are distilled off and the oily residue is fractionally distilled in vacuo.

Zr (NEt ₂ I ₄ is obtained as a pale green liquid (Kp 120 ⁰ C at 0.1 mm).

Yield 68g (80%).

Zr: 23.88% (boron: 24.03%); ¹³ C-NMR in deuterated benzene: δ (CH ₂ ) 43.75 ppm, O (CH ₃ ) 16.35 ppm (23.635 MHz spskum); chemical shifts relative to TMS δ Oppm). All operations except for preparation of the Grignard compound are carried out under argon as inert gas.

Example! The procedure according to Example 1 is repeated, but instead of Zlrkonlumtetrachiorid 83.0g (0.2SmOl) Tltanlumtetrachlorid-bis * Tetrahydrofuran. Distillation under vacuum affords TI (NEtJ) ₄ as an orange colored liquid with a boiling point of

Kp 112'C at 0.1 mm.

Yield 33-42 g (39-60%)

Ti: 14.05% (calculated: 14.23%); ¹¹ C-NMR In deuterated benzene: 8 (CH ₂ ) 45.45 ppm, S (CHi) 15.67 ppm (22.636 MHz spectrum;

chemical shifts ^ relative to TMS 6 Oppm).

Claims (2)

1. A process for the preparation of Tetrakl8 (dialkylemldo) titanium and zirconium, M (NRR ') * (M "Ti, Zr, R, R' a Cr to Cr alkyl group), characterized in that in ethereal solvents titanium or Zirkoniumtetrahalogenld or their Tetrahydrofuranaddukte reacted with Dlalkylamldomagneslumhalogenlden and after filtering off precipitated magnesium salts and the Abdestlllleren the solvent by distillation in vacuo. 2. The method according to item 1, characterized in that the complete separation of the magnesium halides is facilitated by Dioxanzusatz.