Method for preparing dihydroxyalkyl ferrocene dicarboxylate

Abstract

The invention discloses a method for preparing dihydroxyalkyl ferrocene dicarboxylate. The method includes subjecting dimethyl ferrocene dicarboxylate and dihydric alcohol to transesterification in analkane solvent in the presence of an organotin / alkali metal alkoxy composite catalyst to generate a corresponding dihydroxyalkyl ferrocene dicarboxylate compound. The method has the advantages that the reaction conditions are mild, the acid value of the product is low, generated polymerization by-products are few, and the dihydroxyalkyl ferrocene dicarboxylate compound has good process performance when being applied to solid propellants.

Description

technical field [0001] The invention relates to a synthesis method of a ferrocene dicarboxylic acid dihydroxyalkyl ester compound. Background technique [0002] Ferrocene-based combustion performance regulators are currently the most widely used combustion performance regulators for solid propellants. They can be divided into single-core, dual-core and polymers according to their structures; they can be divided into plasticizers according to their functions in solid propellants. Dosage type, adhesive type, co-curing type and energy-containing additive type; according to the type containing the main functional group, it can be divided into alkyl ferrocene type, ferrocene carboxylate type and functionalized ferrocene type. Since ferrocene combustion performance modifiers began to be used in solid propellants in the 1960s and 1970s, the development, evaluation and application of new ferrocene combustion performance modifiers by scholars from all over the world have not stopped....

AI Technical Summary

Problems solved by technology

Adopted two kinds of methods to synthesize ferrocene dicarboxylic acid dihydroxyalkyl ester compound, one: adopt ferrocene dicarboxylic acid and corresponding α, ω-alkyl glycol or oligoethylene glycol are raw materials, Anhydrous hydrogen chloride is used as a catalyst to prepare hydroxyl-containing ferrocene ester compounds, but hydrogen chloride will react with dibasic alcohols, resulting in low product quality; second: ferrocene dicarboxylic acid chloride and corresponding α, ω-alkyl di Preparation of target compound by reaction of polyalcohol or oligoethylene glycol in the presence of catalyst

The preparation method proposed in the patent US6313334 actually produces a mixture of terminal hydroxyl esters with different degrees of polymerization generated by the reaction of ferrocenedicarboxylic acid and diols. The viscosity is relatively high, and the propellant preparation process performance is poor.

In view of the above reasons, Yang Jun, Deng Minzhi and others from the Shanghai Institute of Organic Chemistry proposed a new method in the paper (P249~251) of the 24th Annual Conference of Solid Rocket Propulsion of the Chinese Society of Astronautics "Development of a New Type of Non-migrating Ferrocene Burning Rate Catalyst" (P249~251). A kind of technique for preparing pure ferrocene dicarboxylic acid dihydroxyalkyl ester compound, the process is as follows: 1,1'-ferrocene dicarboxylic acid chloride and diethylene glycol monobenzyl ester are reacted to prepare 1,1'- Diethylene glycol monobenzyl ferrocenedicarboxylate, and then further hydrogenation to obtain 1,1'-diethylene glycol ferrocenedicarboxylate. This compound contains two hydroxyl groups and can be used as a curing agent to participate in the reaction when curing , become a part of the macromolecular structure, and can achieve the purpose of non-migration, but the synthesis process is complicated, the cost is high, the industrial production is difficult, and it is necessary to use toxic ferrocene dicarboxylic acid chloride and benzyl compounds