Based On Vilsmeier Reagents To Reagents To Preagents Amidines And Its Properties

Amidines and derivatives are important in organic chemistry as structural units of many natural products,drug-like molecules,agrochemicals,and synthetic building blocks for numerous heterocyclic compounds.The synthesis of amidine derivatives generally requires pre-activated substrates such as thioamides,aldoximes,etc,which greatly reduces the efficiency of the reaction.Condensation of amides and amines is the most direct and atomically economical method for the synthesis of amidines.However it is difficult to attack nucleophiles to give amidines since amides are weak electrophilic.Therefore,in order to pursue a more common method for synthesis of amidines,we have developed a new method from amides and amines to form amidines based on previous studies.This method not only achieves the condensation of acetamide,but also the lactam.The contents and results of this thesis are as follows:1.Using N,N-dimethylacetamide as the raw material,triphosgene as chlorinating reagent,and the corresponding Vilsmeier reagent is obtained at a low temperature.Then the Vilsmeier reagent is separated by filtration and further combined with aromatic amines or aliphatic amines accompany with triethylamine.Finally,the amidines were obtained,which yield from 21.61%to 71.94%.The optimal conditions to prepare the Vilsmeier reagent:Solvent:anhydrous toluene,temperature:-10-0?,ratio of n(DMAC)and n(BTC):2:1,chlorinating reagent:triphosgene.The conditions for preparation amidine:triethylamine:equivalent or excess,after completion of the addition:heating under reflux.2.Using N-methylcaprolactam as raw material,oxalyl chloride as chlorinating reagent,and the corresponding Vilsmeier reagent is obtained at a low temperature.Then,it is separated by suction filtration,and further combined with an aromatic amine compounds with trimethylamine,which is acid binding agent.Under this condition,the corresponding amidines are prepared,which yield from 37.13%to 78.83%.The optimal conditions to prepare the Vilsmeier reagent:chlorinating reagent:oxalyl chloride,solvent:anhydrous dichloromethane,temperature:-10-0?,reaction time:15 h.The conditions for preparation amidine:trimethylamine:equivalent or excess,after completion of the addition:heating under reflux.3.The intermediates and final products were characterized by 1H NMR,IR,MS and HRMS to determine the structure,as well as to explore the reaction mechanism.