An improved process for selectively N-acylating hydroxy-amino-arylsulfonic acids is disclosed wherein the hydroxy-amino-arylsulfonic acid is dissolved in water by treatment with an alkaline lithium salt, such as lithium hydroxide, and the acylation is conducted while maintaining the pH at about 3-6. The N-acyl-hydroxy-amino-arylsulfonic acids are useful as dyestuff precursors.
本发明公开了一种改进的选择性N-酰化羟基-
氨基-芳基
磺酸的工艺,其中通过使用碱性
锂盐(例如
氢氧化锂)处理使羟基-
氨基-芳基
磺酸在
水中溶解,并在保持pH在约3-6的条件下进行酰化。所得到的N-酰基-羟基-
氨基-芳基
磺酸可用作
染料前体。