Study On The Synthesis Of N3-functionalized Pyrimidinones/Quinazolinones Derivatives Catalyzed By Polymer-supported Sulfonic Acid

Polymer-supported acid catalysts, reagents, and substrates have attracted muchattentions for many years due to their inherent advantages in synthetic chemistry:simplification of reaction procedures including easy separation of products,application to automation systems leading to the combinatorial chemistry, andrecycling of catalysts and reagents. Polymer-supported acid catalysts mainly includepolyethylene glycol （PEG）-bound sulfonic acid, polystyrene-poly （ethylene glycol）（PS-PEG） resin-supported sulfonic acid, pyridinium salt, poly（N-isopropylacrylamide）, polymeric dicyanoketene acetals, polystyrene-boundtetrafluorophenylbis（triflyl）methane and so on.The thesis mainly introduced the development of Polymer-supported acidcatalysts in the organic synthesis. A serious of N3-functionalizeddihydropyrimidinones and quinazolinones were synthesized under Polyethyleneglycol （PEG）-bound sulfonic acid and Polystyrene-poly （ethylene glycol）（PS-PEG）resin-supported sulfonic acid. These synthesis methods have the advantages of simpleoperation, high yields and high regioselectivity, especially in environmentally friendlyconditions, which supplies a new method to synthesis new compounds.This thesis includes four Parts:Chaper One: In this section we mainly introduced the new advances andapplications of some Polymer-supported acid catalysts in the organic synthesis, suchas, PEG-OSO₃H、PS-PEG-OSO₃H、pyridinium salt、polymeric dicyanoketene acetals.Chaper Two: Polyethylene glycol （PEG）-bound sulfonic acid was applied asefficient and recyclable polymeric catalyst for the synthesis of N3-functionalized3,4-dihydropyrimidones/quinazolinones from three-component reactions between3,4-dihydropyrimidones/quinazolinones with paraformaldehyde and severalnucleophiles, such as, alcohols/phenol/benzenethiol/sodium azide. The advantages ofthis method are fast reaction rate, simple procedure, easy separation of products, andrecycling of catalyst.Chaper Three: In order to compare the catalytic ability of PEG-OSO₃H andPS-PEG-OSO₃H, the reactions catalyzed by PS-PEG-OSO₃H were also investigated. N3-functionalized DHPMs and quinazolinones were successfully obtained.Subsequently, the reactions between DHPM substituted with2-hydroxy on thearomatic ring and propionaldehyde, butyraldehyde,3-methylbutanal were examined,and to our delight, reaction of2-hydroxy substituted DHPM with propionaldehydegave the3,4,6,11b-tetrahydrobenzo[e]pyrimido[1,6-c][1,3]oxazine with high yields.Chaper Four: Under mild reaction conditions, the reaction of2-amino-5-aryloxymethylene-1,3,4-thiadiazoles with p-TsOH·H2O, sodium nitriteand potassium bromide in acetonitrile solvent afford8new2-bromo-5-aryloxymethylene-1,3,4-thiadiazoles in excellent yields.