Green and efficient deep eutectic solvent mediated one-step synthesis of Suxamethonium Chloride as Active Pharmaceutical Ingredient

There is ever-growing pressure on the pharmaceutical industry to timely produce quality and affordable medicines in a sustainable manner. Herein, we demonstrated an efficient and green one-step ZnCl2-ChCl DES-mediated synthetic protocol for an important pharmaceutical active ingredient, Suxamethonium chloride via esterification of either succinic acid or succinic anhydride where DES acted as catalyst, solvent and starting material. The one-pot esterification conversion of either succinic acid or succinic anhydride to Suxamethonium chloride was excellent (>97 % and 92% after recrystallisation) under the following optimal conditions: succinic acid or succinic anhydride (1 eq.), choline chloride (4 eq.), ZnCl2 (4 eq.), and H2SO4, (0.2 eq.) at 150 °C for 2 h. The use of DES as reagent, solvent and catalyst resulted in sustainable, novel, and efficient one-step synthesis of active pharmaceutical ingredient: Suxamethonium chloride.