Selective acylation of hydroxy-amino-arylsulfonic acids
AssigneeAmerican Hoechst Corporation
InventorsAnthony J. Corso, Kathleen M. Colavito, Thomas S. Phillips
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Abstract
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.
Claims15
In a method for making an N-acylated hydroxy-amino-arylsulfonic acid which comprises dissolving said hydroxy-amino-arylsulfonic acid in aqueous solution and reacting it with an acylating agent, the improvement which comprises forming a lithium salt of said sulfonic acid in aqueous solution and conducting the acylation reaction at a pH of about 3 to 6.
A method for making an N-acylated hydroxy-amino-arylsulfonic acid which comprises dissolving an hydroxy-amino-arylsulfonic acid in aqueous solution by treatment with an alkaline lithium salt to form a lithium salt of said sulfonic acid, and reacting said lithium salt of said sulfonic acid with an acylating agent while maintaining said aqueous solution at a pH of about 3 to 6.
Dependencies are inferred from the claim text.