A method for producing meta-xylylenediisocyanates includes a reaction step in which monohalogenated benzenes, formaldehydes, and an amide compound represented by general formula (1) below are allowed to react in the presence of an acidic liquid to produce a bisamide compound; a dehalogenation step in which in the bisamide compound, the halogen atom derived from the monohalogenated benzenes is replaced with a hydrogen atom; and a thermal decomposition step in which the bisamide compound from which the halogen atom is eliminated is subjected to thermal decomposition. In the reaction step, the acidic liquid contains inorganic acid, the equivalent ratio of the hydrogen atom of the inorganic acid relative to the monohalogenated benzenes is more than 14, the acidic liquid has an acid concentration of more than 90 mass%, and the reaction temperature is more than 10°C. General formula (1):
(in general formula (1), R1 represents an alkoxy group or an amino group).
一种生产偏二
甲苯基
异氰酸酯的方法包括一个反应步骤,在该步骤中,单卤化苯、
甲醛和由下式(1)代表的酰胺化合物在酸性液体存在下反应生成双酰胺化合物;脱卤步骤,在该双酰胺化合物中,用氢原子取代来自单卤化苯的卤素原子;以及 热分解步骤,对消除了卤素原子的双酰胺化合物进行热分解。在反应步骤中,酸性液体含有
无机酸,
无机酸的氢原子相对于单卤代苯的当量比大于 14,酸性液体的酸浓度大于 90%,反应温度大于 10℃。通式(1):
(在通式(1)中,R1 代表烷氧基或
氨基)。