Iodotrimethylsilane preparing by dissolving and adding iodine

Abstract

The invention provides an iodotrimethylsilane preparation method. The preparation method comprises the following steps that half hexamethyldisilane is put in a reaction flask, a layer of rectifying column packing glass springs is added in a constant pressure dropping funnel, then elementary substance iodine and half hexamethyldisilane are added in the constant pressure dropping funnel, vacuumizing and nitrogen replacing are performed on a reaction system, and all the steps are repeated for three times; stirring is started, the temperature rises to 65 DEG C, and hexamethyldisilane solutions of the iodine are dropwise added; after dropwise adding is finished, the outer temperature rises to 130 DEG C for backflow, and therefore after being cooled, steam enters the constant pressure dropping funnel to dissolve the undissolved iodine in the constant pressure dropping funnel; after the iodine is dissolved completely and dropwise added in the reaction system, reaction is performed for 2 hours until the reaction is complete; heating is stopped, the temperature is cooled below 30 DEG C, a reaction device is changed into a distillation device to collect main distillate fractions, and then colorless liquid iodotrimethylsilane competitive products are obtained.

Description

technical field [0001] The invention relates to a preparation method of iodotrimethylsilane. Background technique [0002] Iodotrimethylsilane is widely used in the fields of drug synthesis and organic synthesis. In drug synthesis, trimethyliodosilane is often used as a protective reagent for functional groups such as hydroxyl groups, especially in the fourth-generation cephalosporins such as cefepime and cefepime. Luo's synthetic process has been widely used. Iodotrimethylsilane is active in nature and easily reacts with oxygen in the air to deteriorate, which limits its storage and use. [0003] There are more than 10 synthetic methods of iodotrimethylsilane, and the more practical and industrialized synthetic methods are the reaction of hexamethyldisiloxane with iodine and aluminum powder, and the reaction of hexamethyldisilane with iodine. The trimethyliodosilane currently on the market contains a lot of low-boiling impurities (such as tetramethylsilane and dimethyldii...

AI Technical Summary

Problems solved by technology

Trimethyliodosilane is active, and it is easy to react with oxygen in the air and deteriorate, which limits its storage and use.

The operation steps of this method include adding refined iodine in batches. Because iodine has a high vapor pressure, it is easy to sublime, has a pungent smell, and is easy to condense after sublimation. It is toxic and corrosive, so this step of operation pollutes the environment and is serious. Harm the operator; more importantly, the amount of iodine added to the reactor cannot be accurately determined, because some iodine has sublimated into the environment in the process of adding iodine in batches, and this method can only add excessive iodine, i.e. iodine and The molar ratio of hexamethyldisilane is greater than 1, iodine is very expensive relative to hexamethyldisilane, and the cost of this method is high; due to the excessive iodine added, the crude product of iodotrimethylsilane needs to be further refined. step, the amount of copper powder is large, which is not conducive to the reduction of production cost; in the process of adding iodine in batches, air and water vapor will be introduced, resulting in many side reactions, and the product needs to be further refined; the added solid iodine has a slow reaction; the method The operation steps include the refining of iodotrimethylsilane, and copper powder needs to be added, so the reaction kettle needs to be cleaned of copper powder and other impurities before it can be used further, and continuous production is not possible.