Continuous method for preparation of dihalogenated alkane from diol compound

Abstract

The invention discloses a continuous method for preparation of dihalogenated alkane from a diol compound. A diol compound and haloid acid are used as the substrate, a microchannel reactor is utilizedto synthesize dihalogenated alkane continuously. Synthesis of the dihalogenated alkane includes the steps of: inputting the diol compound and haloid acid into a mixer respectively by a metering pump at room temperature, conducting premixing, then sending the mixture into a high-temperature section of the microchannel reactor at for reaction, and controlling the reaction temperature by an externalcirculating heat exchange system; at the end of the reaction, letting the product flow out from an outlet of the microchannel reactor and enter a cooling section, letting the cooled material enter a liquid separation kettle for standing and liquid separation, and collecting an organic layer; and preheating the organic layer, then feeding the preheated organic layer into a rectifying tower by a metering pump, controlling the temperature and reflux ratio of a reboiler, and collecting fractions at a specific temperature, thus obtaining the target product in a product collecting tank. The method provided by the invention has the characteristics of high reaction efficiency, safety, environmental protection, convenience and rapidity.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a continuous method for preparing dihaloalkanes from diol compounds. Background technique [0002] Dihaloalkanes are widely used in the field of traditional fine chemicals, especially as hydrophobic groups and alkylating groups in the molecules of drugs, pesticides and surfactants, which play an irreplaceable role. With the development of biomedical technology, visual diagnostic reagents used for preoperative diagnosis, surgical planning or mid-term evaluation have gradually become the darling of surgeons. Among them, near-infrared fluorescence molecular diagnostic technology has developed particularly rapidly, and near-infrared fluorescence technology has good tissue penetration. , small scattering, low background fluorescence, very suitable for clinical in vivo imaging. [0003] At present, indocyanine green has been approved for clinical use as an imaging agent for liver can...

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Problems solved by technology

[0004] The general method for the production of dihaloalkanes is the nucleophilic substitution reaction of diols and thionyl chloride, but this method has large pollution, poor atom economy, high cost, and is not suitable for the production of other halogenated hydrocarbons except chlorination.

[0005] With the strengthening of environmental protection awareness, people began to try to use the reaction of hydrochloric acid and diols to produce dihaloalkanes. This method is economical and environmentally friendly, but the reaction efficiency is low, the yield is low, and the reaction time is long, which cannot meet the requirements of industrial production.

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