Study On The Cycloaddition Reaction Of α-halo-N-benzoylhydrazone

Pyridazine,pyrazole and diazepine structures are multifunctional structural units in many natural products and pharmaceutically active compounds.The aza-alkenes in situ generated from a-halogenated-N-benzoylhydrazone are important intermediates for the synthesis of various five-membered and six-membered nitrogen-containing heterocycles,which have been widely used in cycloaddition reactions.Therefore,in this paper,a series of biologically active spiro[indoline-3,3’-pyridazine]-2-one,spiro[indoline-3,3’-[1,2,4]triazine]-2-one,tetrahydrotriazine,[dihydropyrazol-1,5-diyl]bis[benzophenone],dihydrospiro[indoline-3,5’-[1,2]diazepines]derivatives were successfully synthesized by base promoted cycloaddition reaction of α-halo-N-benzoylhydrazones.1.The[4+2]cycloaddition reaction of a-halo-N-benzoylhydrazones with 3-arylideneoxindoles at room temperature in dichloromethane was studied.Seventeen spiro[indoline-3,3’-pyridazine]-2-one derivatives were obtained in high yield and with high diastereoselectivity.Thirteen spiro[indoline-3,3’-[1,2,4]triazine]-2-one derivatives were synthesized in good yields by the reaction of 3-imino-2-indolone derivatives with a-halo-N-benzoylhydrazone under the same reaction conditions.Thirteen tetrahydrotriazine derivatives were synthesized by using imine instead of 3-imino-2-oxindole derivatives under the same reaction conditions.The structures of the synthesized compounds were characterized by 1NMR,13C NMR,HRMS and IR spectra.The single crystal structures of eight compounds were determined.2.The triethylamine promoted two-component reaction of a-halogenated-N-benzoylhydrazones and 4-dimethylaminopyridinium bromides in dry dichloromethane at room temperature was studied.Fourteen[dihydropyrazol-1,5-diyl]bis[benzophenone]derivatives were synthesized in high yields.The reaction has the advantages of easy availability of raw materials,simple reaction conditions,wide range of substrates,wide group tolerance,high yields,and high diastereoselectivity.The structures of the synthesized compounds were characterized by 1H NMR,13C NMR,HRMS and IR spectra.The single crystal structures of two compounds were determined.3.The[4+3]cycloaddition reaction of isatin MBH carbonates withα-halo-N-benzoylhydrazones was carried out in dry dichloromethane at room temperature in the presence of DABCO as base.Isatin MBH carbonates with different structures showed different diastereoselectivities.The structures of 21 dihydrospiro[indoline-3,5’-[1,2]diazepine]derivatives were synthesized.The direct alkylation reaction of isatin MBH nitriles and a-halo-ketone oximes generated 12 substituted chain compounds.The structures of the synthesized compounds were characterized by 1H NMR,13C NMR,HRMS and IR spectra.The single crystal structure of one compound was determined.