Study On The New Synthetic Methods Of 2-amino-8-hydroxyquinoline

2-amino-8-hydroxyquinoline was synthesized by the N-oxidation,sulfonyltion, amination reaction,when 8-hydroxyquinolin was used as raw material.Based on reaction mechanism,influences of factors on N-oxidation,sulfonyltion,amination were optimized and the optimal reaction conditions was obtained.Furthermore,effects of different of amination agent on product yield and selectivity was investigated in this article.The optimal synthesis route of the target compound 2-amino-8-hydroxyquino was determined based on the optimal reaction conditions of unit reaction.The experiments result showed that the optimal conditions of N-oxidation was 4.35g 8-hydroxyquinoline 3mL hydrogen peroxide,6mL acetic acid,3mL acetic anhydride,the reaction temperature at 20℃,reaction time was 10h,and hydrogen peroxide was added by two batches,the yield was 89.6%.the optimal conditions of amination reaction was amination agent NH3·H₂O at the same time continuing bubble ammonia gas.the optimal materials ratio was 1.61g 8-hydroxyquinoline nitrogen oxide,2.5g TsC1,sulfonyl time 1h,the amount of ammonia 3mL,amination time 2h,the yield was 76.2%.The overall yield was 68.3%.The structure of target compound 2-amino-8-hydroxyquino was characterized by HNMR,MSand IR.