1. The first step of the reaction, the reaction time is too long, and there are impurities. After the addition is complete, timely control is required and the reaction is processed in time.2. The fourth step is the most difficult step of the reaction, the yield cannot be improved, and the product cannot be obtained which is not resolved at present,. 3. The melting point of the final product is low. It can be dissolved with petroleum ether, and it can be crystallized with a small amount of solvent.
1. The first step of the reaction, the reaction time is too long, and there are impurities. After the addition is complete, timely control is required and the reaction is processed in time.<br>2. The fourth step is the most difficult step of the reaction, the yield cannot be improved, and the product cannot be obtained which is not resolved at present,<br>. 3. The melting point of the final product is low. It can be dissolved with petroleum ether, and it can be crystallized with a small amount of solvent.
正在翻译中..