利用霍夫曼(Hofmann)降解反应由邻苯二甲酰亚胺制备邻氨基苯甲酸是一个较好的实验训练。因此,多年来我校一直把它按排在基础有机实验课程中。但实验中遇到一些问题,如产品颜色往往较深,收率一般较低。为了提高教学质量,我们围绕以上两个问题进行了初步摸索。发现在加溴量一定的情况下影响颜色的主要因素是反应温度。当然加大溴量也容易使产品颜色加深。特别是在原操作条件下(参看下段),加大溴量不但会影响产品颜色,而且会影响到收率。当我们把原操作中“自然反应”改为“控制升温”时得到了颜色 Preparation of anthranilic acid from phthalimide by Hofmann degradation reaction is a good experimental training. Therefore, our school has been pressing it for many years in basic organic experimental courses. However, some problems encountered during the experiment, such as product color is often deeper, the yield is generally lower. In order to improve the quality of teaching, we conducted a preliminary exploration around the above two issues. It is found that the main factor affecting the color in the case of a certain amount of bromine is the reaction temperature. Of course, increasing the amount of bromine is also easy to make the product color deepened. Especially under the original operating conditions (see the next paragraph), increasing the amount of bromine will not only affect product color, but also affect the yield. When we changed the “natural response” in the original operation to “control warming”, we got the color