Synthesis of 3-Methyl-6-aminomethyl Quinoxaline-2-carboxylic Acid Derivative
Novel 3-methyl-6-aminomethyl-quinoxaline-2-carboxylic acid derivatives were synthesised by introducing two reactive groups(—NH2,—COOH)into the original structure of 3,4-diaminoben-zonitrile to couple with carrier proteins,which have a better potential value in organic drug intermedi-ates.A 3-methyl-6-aminomethyl-quinoxaline-2-carboxylic acid derivative was designed and synthesized using 3,4-diamino benzonitrile,ethyl acetoacetate and N-bromosuccinimide(NBS)as raw materials through three steps of nucleophilic addition and elimination,hydrogenation reduction and sodium hy-droxide hydrolysis.Its structure was characterized by 1H NMR,13 C NMR and MS(ESI).And opti-mize the types of hydrolysis reagents for key synthesis processes(as well as the ratio of optimal sub-stance quantity,the type of solvent in hydrogenation reduction,the type of hydrolysis reagent,and the optimal reagent dosage).The results showed that the reaction yield was 56%when the feeding ratio(the ratio of the amount of substances)of 3,4-diaminobenzonitrile to ethyl acetoacetate was 1∶1.In the hydrogenation reduction reaction,ethanol is the solvent with the highest yield of 44%.In the reac-tion of esterification and hydrolysis to carboxylic acid,when the hydrolysis catalyst is sodium hydrox-ide,and the ratio of the amount of sodium hydroxide to the amount of raw material is 3∶1,the reaction effect is the best,and the product yield is 97%.