Synthesis And Properties Of Benzoxazine And Quinazolinone Derivatives

The aza-Wittig reaction is a kind of reaction that the iminophosphorane compound reacts with the carbonyl compound to convert the P = N bond to the C = N bond,which is one of the most important methods for constructing the C = N bond.The reaction conditions are mild with high yield,easy operation and so on.And the reactions are widely used in the synthesis of various organic compounds.In recent years,organophosphorus catalyzed reaction has received more and more attention,making the catalytic aza-Wittig reaction more and more attention.We can try to design a more efficient catalytic aza-Wittig reaction to synthesize various compounds based on chassic aza-Wittig reaction.Benzoxazine compounds have good biological activity and are used as important pharmaceutical intermediates and active compounds.Such as:anti-TB drugs,analgesics,antifungal,anti-microbial agents.Quinazolinones are also a class of high potential heterocyclic compounds with good biological activity,and they are commonly used in the treatment of hypertension,antifungal,anti-cancer agents.As the above two kinds of compounds have a very broad application prospects,therefore,developing new synthetic methods to them is of great significance.In this paper,4H-3,1-benzoxazine compounds were synthesized by the Passerini and catalytic Staudinger/aza-Wittig reaction,and the quinazolinones were synthesized by dehydration of some ureas.The synthesis conditions and spectral properties of the above target compounds were analyzed and studied.The specific contents are as follows:1.The recent advances in the synthesis of benzoxazine compounds,quinazolinones and the latest advances in aza-Wittig reactions have been reviewed.2.In this paper,the Passerini reaction of 2-azidobenzaldehyde,isocyanide and acid occurred to generate azide intermediate Ⅱ-1,and then the catalytic Staudinger/aza-Wittig reaction was carried out in the presence of cyclic phosphine oxide,reducing agent TMDS and Ti(i-PrO)4 to produce 4H-3,1-benzoxazine II-2 in moderate yield.3.In this paper,the reaction of isatin anhydride,with benzylamine or aromatic amine to produce amide derivatives Ⅲ-1,which was then transformed into urea,and then with the formation of intermediate esters of urea Ⅲ-2.Futher dehydration of the ureas in the presence of PPh3,C2Cl6 and NEt3 produced the target product quinazolinone derivatives Ⅲ-3.