21116-65-4

Upstream product

• 34907-60-3 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane 
• 80-10-4 diphenylsilyl dichloride 

Downstream Products

• 24070-94-8 N,N'-bis(hydroxydiphenylsilyl)tetramethylcyclodisilazane 
• 21116-67-6 1,3-Bis-(diphenylmethylsilyl)-2,2,4,4-tetramethyl-cyclodisilazan 

Relevant academic research and scientific papers

Preparation method of cyclodisilazane

The invention relates to a preparation method of a cyclodisilazane compound shown as a formula (I), which comprises the step of preparing cyclodisilazane shown as the formula (I) from a 1, 3-dihalodisilazane compound shown as a formula (II), wherein the formulas are described in the specification. Compared with a traditional high-temperature rearrangement method and a method for preparing 1, 3-bis(chlorodiorganosilyl) cyclodisilazane through high-temperature high-compression polymerization and exchange reaction, the preparation method of cyclodisilazane provided by the invention has the advantages of low reaction temperature, short reaction time, few byproducts, high yield and capability of efficiently preparing cyclodisilazane compounds with different structures; compared with a method of lithiating butyl lithium and then removing lithium chloride to form a reaction ring, the method has the advantages that the reaction can be completed in one step, the process is simple and easy to control, and the cost is low; and moreover, the preparation method is high in safety, easy to control, low in cost, environmentally friendly and beneficial to large-scale production.

Synthesis of 1,3-bis(chlorodiorganosilyl)-cyclodisilazane via dehydro-chlorination reaction of 1,3-dichloro-Tetraorgano-Disilazane in the presence of deacidification agent

A novel convenient synthesis process for 1,3-bis(chlorodiorganosilyl)-cyclodisilazanes is developed via an intermolecular dehydrochlorination of 1,3-dichloro-tetraorgano-disilazane, in the presence of a strong organic alkaline deacidification agent 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). This procedure involves a one-step process under mild synthesis condition, with higher production efficiency and product purity as compared to those of the previously reported methods. The formation of 1,3-bis(chlorodiorganosilyl)-tetraorgano-cyclodisilazane occurs via the primary dehydrohalogenation of intermolecular 1,3-dichloro-tetraorgano-disilazanes to trisilylamine structure with a subsequent ring closure. The silicon atoms with different exocyclic or endocyclic substituents are closely related to the steric hindrance of the substituents. Dehydrochlorination reactions occur more readily on the chlorine atoms attached to the silicon atoms with substituents possessing relatively low steric hindrance. Four 1,3-dichloro-tetraorgano-disilazanes for the synthesis of 1,3-bis(chlorodiorganosilyl)-cyclodisilazanes are prepared. The investigation into the reaction mechanism shows that the equilibrium reaction of cyclosilazane with diorgano-dichlorosilane is a more straightforward and efficient method in the preparation of 1,3-dichloro-tetraorgano-disilazanes, as compared to the trans-silylation reaction of hexamethyl-disilazane with diorgano-dichlorosilane.

Synthesis method of 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane

The invention discloses a synthesis method of 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane. The method comprises the following steps: (1) carrying out reaction on diphenylchlorsilane and tetramethyldisilazane to obtain 1,1-diphenyl-3,3-diphenyldisilazane disclosed as Formula I; (2) in an organic solvent, carrying out chlorination reaction on the 1,1-diphenyl-3,3-diphenyldisilazane and a chlorination reagent to obtain 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane disclosed as Formula II; and (3) in an organic solvent, carrying out lithiation reaction on the 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane and a lithium alkylide reagent, and carrying out cyclization reaction to obtain the 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane disclosed as Formula III. The method has the advantages of simple synthesis route, mild conditions, simple product after-treatment, high product purity and higher product yield.

Method for synthesizing 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane by non-high-temperature exchange process

The invention discloses a method for synthesizing 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane by a non-high-temperature exchange process. The method comprises the following steps: 1) mixing dichlorodiphenylsilane and hexamethylcyclotrisilazane, and carrying out ring opening rearrangement reaction to obtain a 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane-byproduct mixture; 2) adding a reducer into the mixture obtained in the step 1), carrying out reduction reaction, and fractionating to obtain 1,1-dimethyl-3,3-diphenyldisilazane; 3) carrying out chlorination reaction on the 1,1-dimethyl-3,3-diphenyldisilazane, and separating to obtain pure 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane; and 4) carrying out lithiation reaction on the 1,3-dichloro-1,1-dimethyl-3,3-diphenyldisilazane, and carrying out cyclization reaction to obtain the 1,3-di(diphenylchlorosilyl)-2,2,4,4-tetramethylcyclodisilazane. The method has the advantages of simple route and mild conditions, and does not need to perform reaction under high-temperature conditions. The product is simple in after-treatment and higher in yield.