Reaction system for safely adding tert-butyllithium into reactor

Abstract

The invention provides a reaction system for safely adding tert-butyllithium into a reactor. The reaction system comprises a reaction device, a cooling device, a gas protection device and an injector. The reaction device comprises a reaction bottle, a stirring paddle tightly connected to an opening in the middle of the reaction bottle in a sleeved mode and a motor arranged at the upper end of the stirring paddle; the cooling device is arranged under the reaction bottle; the gas protection device is connected with an opening in the right side of the reaction bottle through a three-way valve; the injector comprises a syringe needle, a piston and a needle cylinder, the syringe needle is inserted into a rubber plug to be connected with an opening in the left side of the reaction bottle, the piston is connected with an air cylinder, a cooling layer is arranged on the periphery of the needle cylinder, a reinforcing device is arranged on the periphery of the joint of the syringe needle and the needle cylinder, and a fastening device is arranged on the periphery of the joint of the rubber plug and the opening in the left side of the reaction bottle. The reaction system has the advantages of being simple in structure, reasonable in design, high in automation degree, capable of saving time and labor, safe and convenient in sampling, good in sealing effect and wide in application and has the wide application range.

Description

technical field [0001] The invention relates to the technical field of chemical reagent adding systems, in particular to a reaction system for safely adding tert-butyllithium to a reactor. Background technique [0002] In chemical organic synthesis experiments, superbasic organic lithium reagents, such as tert-butyllithium reagents, are sometimes needed. In order to stabilize the properties of commercial products, it is usually n-pentane solution. However, this reagent is highly flammable and can spontaneously ignite in the air. It must be protected with dry nitrogen during storage and must be handled with great care. In the prior art, laboratories generally use ordinary plastic syringes to transfer n-pentane solutions of tert-butyllithium. This reagent is used for dehalogenation reactions or halogen-lithium metal exchange reactions are generally carried out under low temperature conditions, such as tens of degrees below zero. , this type of reaction is an exothermic reacti...

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Problems solved by technology

However, this reagent is highly flammable and can spontaneously ignite in the air. It must be protected with dry nitrogen during storage and must be handled with great care.

In the prior art, laboratories generally use ordinary plastic syringes to transfer n-pentane solutions of tert-butyllithium. This reagent is used for dehalogenation reactions or halogen-lithium metal exchange reactions are generally carried out under low temperature conditions, such as tens of degrees below zero. , this type of reaction is an exothermic reaction, so the addition rate of the reagent has a great influence on the temperature of the reaction system and thus affects the quality of the reaction. Therefore, the reagent needs to be injected slowly, especially when the reaction volume is relatively large, and the feeding time often needs to be several hours

In addition, the needle and barrel of the syringe are easy to fall off, causing the risk of tert-butyllithium reagent leakage

Due to improper operation when using tert-butyl lithium reagent, poor sealing of equipment, insufficient air replacement or solvent, reagent water, etc., fire accidents caused by tert-butyl lithium naturally occur frequently. If the impact is relatively large, Tsinghua laboratory explosion accident last year

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