申请人:Mitsui Toatsu Chemicals, Incorporated
公开号:US04302396A1
公开(公告)日:1981-11-24
Novel chlorinated 4-methylphthalic acids or anhydrides of the general formula ##STR1## wherein n is an integer of 1, 2 or 3, with the proviso that when n is 1, the chlorine atom is positioned at 3- or 5-position and when n is 2, the chlorine atoms are positioned at 3- and 5-positions. The new compounds are produced by dissolving 4-methylphthalic anhydride in concentrated sulfuric acid or fuming sulfuric acid to form a solution, and reacting the solution with chlorine at room temperature preferably in the presence of a catalytic amount of iodine, thereby to yield a crude product containing a mixture of chlorinated 4-methylphthalic acids. By subjecting the mixture to a thermal dehydration treatment in an inactive organic solvent, each of the chlorinated compounds may be isolated as its corresponding anhydride in the form of crystals. These chlorinated 4-methylphthalic anhydrides are valuable as intermediates for the preparation of dyestuffs or pigments.
新的氯代4-甲基邻苯二甲酸或酐化物的化学式如下:##STR1## 其中n是1、2或3的整数,但当n为1时,氯原子位于3-或5-位置,当n为2时,氯原子位于3-和5-位置。这些新化合物通过将4-甲基邻苯二甲酸酐溶解在浓硫酸或烟雾硫酸中形成溶液,并在室温下与氯反应(最好在碘的催化下)���从而得到含有混合氯代4-甲基邻苯二甲酸的粗产品。通过在无活性有机溶剂中对混合物进行热脱水处理,可以将每种氯代化合物作为其相应的酐以晶体形式分离出来。这些氯代4-甲基邻苯二甲酸酐是制备染料或颜料的中间体,具有重要的价值。