Overview of the preparation of hydrogen fluoride pyridine
In the manufacturing process of organic fluorine chemicals, some fluorine-containing acid fluoride compounds are often produced as intermediates in the process, such as hydrogen fluoride boric acid-10B pyridine. It can be used as an intermediate in laboratory research and development processes and chemical and pharmaceutical synthesis processes.
Preparation and Application of Hydrogen Fluoride Pyridine
1) Prepare a glass substrate etching solution for flat panel display. The etching solution consists of hydrogen fluoride pyridinium salt, strong acid, water and ethylenediaminetetraacetic acid. The percentages of each component in the total weight of picolidine chromium in the etching solution are: hydrogen fluoride pyridinium salt: 10-20%; strong acid: 30-70%; ethylenediaminetetraacetic acid: 0.5-5%; the balance is water. This etching solution is a safe, stable, and efficient etching solution that can well solve the problem of insoluble by-products produced during the etching process, and also improves the etching rate and etching effect. This etching solution is suitable for thinning glass substrates such as TFT.
2) Preparation of idecalcitol, including the following steps: 1) Coupling the A ring fragment with the formula (I) structure and the CD ring fragment with the formula (II) structure under the action of a catalyst, and reacting After completion, extraction and drying are performed, and the intermediate of formula (III) structure is obtained by column chromatography separation and purification; 2) Dissolve the intermediate obtained in step 1) in a tetrahydrofuran solution, add hydrogen fluoride pyridine to remove the silicon ether protecting group, and then Purify and crystallize to obtain the finished product of idecalcitol. In the preparation method of idecalcidol of the present invention, the yield of coupling the A ring and the CD ring is increased from 26% to 49%, and the yield of removing the silicon ether protecting group is slightly increased.
Preparation of hydrogen fluoride pyridine
Hydrogen fluoride pyridine is prepared as follows:
1) In a reaction kettle with a stirrer, add 32 kilograms of methanol, and slowly add 79 kilograms of pyridine under stirring to mix the two evenly to obtain a mixture of methanol and pyridine;
2) Transfer the mixture of methanol and pyridine obtained above into a closed reaction kettle with a stirrer. At room temperature 0℃, start stirring, slowly add kilograms of perfluorooctanoyl fluoride to the mixture of methanol and pyridine by dropwise addition, and continue stirring for 2 hours after the addition is completed;
3) Transfer the reaction product obtained above to the column still of a distillation tower with 60 theoretical plates, perform distillation, and obtain 395 kilograms of methyl perfluorooctanoate (about 96% yield). 115 kilograms of the mixture are recovered, which is mainly hydrogen fluoride pyridine, a complex of pyridine and hydrogen fluoride, which can be directly used in the fluorination reaction without other treatment.
