Synthesis And Application Of Benzothiadiazine 1,1-dioxide And 4,5-2H-pyridazone Compounds

With the increasingly prominent environmental security issues,people have a deeper understanding of green organic synthesis.To reduce the use of toxic substances and reduce the generation of pollutants,it becomes extremely necessary to develop alternative methods to perform organic synthesis reactions under environmentally benign conditions.In this thesis,benzothiadiazine 1,1-dioxides and 4,5-2H-pyridazones were synthesized without solvents and catalysts.And three compounds with important pharmacological activities,thiabutazide,ethylthiazide and teclothiazide,were further synthesized.The synthesis of benzothiadiazine 1,1-dioxides was studied in this thesis.The reaction time and temperature were optimized in solvent-free and catalyst-free conditions by using o-aminobenzenesulfonamide and benzaldehyde as the reaction model.Based on that,26 different substituted benzothiadiazine-1,1-dioxides were synthesized,all of which achieved good yields and purities,and this method is highly substrate applicable with atomic economy.The synthesis of 4,5-2H-pyridazones was studied in this thesis.The reaction time,temperature and material ratio were optimized in solvent-free and catalyst-free conditions by using 3-Benzoylpropionic acid and phenylhydrazine as the reaction model.Under optimal conditions,19 different substituted 4,5-2H-pyridazones were synthesized.The method can obtain the target compounds in good yield with rapid reaction and simple post-treatment.Based on the above work,thiabutazide,ethiazide,and teclothiazide were further synthesized in this work.While optimizing the reaction temperature,time,and material ratio under solvent-free and catalyst-free conditions,thiabutazide,ethiazide and teclothiazide were synthesized from 4-amino-6-chloro-1,3-benzenedisulfonamide and substituted aldehydes(Isovaleraldehyde,Propionaldehyde or Chloral)in good yield and purity.