苯佐卡因的制备.doc

苯佐卡因的制备
[摘要]
本实验的主要目的是以多步骤的综合性学生实验合成苯佐卡因(对氨基苯甲酸乙酯)并了解其物理、化学性质。同时也促进学生对重结晶,抽滤,熔点测试,分液等基本操作的掌握。苯佐卡因是一种白色针状晶体,无臭,味微苦而麻,遇光渐变黄色,易溶于乙醇、***、***仿等,难溶于水,临床上一般用作局部麻醉剂。本实验是以对氨基甲苯为原料,先与醋酸反应经酰化得对***乙酰苯***,再与高锰酸钾反应经氧化得到乙酰氨基苯甲酸,然后加盐酸经水解得到对氨基苯甲酸,最后加乙醇经酯化得到产品。由于该有机合成实验步骤多及实验操作上的失误,使得最终产率较低,但经多种中间产物的熔点测定与最终产物的红外光谱测定可以基本确定已成功合成了苯佐卡因,同时实验技能得到了一定锻炼。
[关键词]苯佐卡因; 合成;
[ABSTRACT] The main purpose of this study is to synthesize benzocaine by multi-prehensive experiment and to understand its physical and chemical properties. It also can encourage students to master crystallization, filtration, melting point test, liquid and other basic operations . Benzocaine is a white acicular crystal powder, odorless, slightly bitter taste and hemp, meets the light gradient yellow, soluble in ethanol, ethyl ether, chloroform, but hardly soluble in water, and it is generally used as a local anesthetic. Raw material of the experiment is para-aminotoluene. It and acetic acid reaction to n-methylacetanilide. N-methylacetanilide and potassium permanganate reaction to acetamidobenzoic acid. Acetamidobenzoic acid and hydrochloric acid reaction to para-aminobenzoic acid. Para-aminobenzoic acid and alcohol reaction to benzocaine. Due to so many synthesis experimental steps and experimental operational error, the final yield is low. But a variety of intermediate products is determined by melting point and final product is determin