Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by ...Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.展开更多
2-Amino-5-methylbenzoic acid（1） was acylated with acyl chlorides,then heated（together） with（acetic） anhydride to give 2-phenyl or 2-benzyl-6-methylbenzoxazin-4-one（3a3b）,while compound 1 was （reacted） with p...2-Amino-5-methylbenzoic acid（1） was acylated with acyl chlorides,then heated（together） with（acetic） anhydride to give 2-phenyl or 2-benzyl-6-methylbenzoxazin-4-one（3a3b）,while compound 1 was （reacted） with propanoic anhydride or trifluoroacetic anhydride to give 2-ethyl or 2-trifluoromethyl-6-methylbenzoxazin-4-one（3c3d） directly. Then,2-substituted 6-methylbenzoxazin-4-ones（3a3d） were heated together with formamide to afford 2-substituted 6-methyl-4（3H）-quinazolinones（4a4d）,which were（converted） into the title compounds（5a5d） via brominating with N-bromosuccinimide in the presence of （PhCOO）2.The structures of all the intermediates and final products were confirmed with ESI-MS,1H NMR and elemental analysis.展开更多
文摘Dihydroquinazolin-4(3H)-ones were synthesized by the reaction of o-nitrobenzamides with aromatic aldehydes or cyclones promoted by the low-valent titanium reagent(TiCl 4-Zn system). The products were characterized by elementary analysis, IR, 1H NMR and X-ray single crystal diffraction. This method possesses the advantages of easily accessible starting materials, convenient manipulation and moderate to high yields.
文摘2-Amino-5-methylbenzoic acid（1） was acylated with acyl chlorides,then heated（together） with（acetic） anhydride to give 2-phenyl or 2-benzyl-6-methylbenzoxazin-4-one（3a3b）,while compound 1 was （reacted） with propanoic anhydride or trifluoroacetic anhydride to give 2-ethyl or 2-trifluoromethyl-6-methylbenzoxazin-4-one（3c3d） directly. Then,2-substituted 6-methylbenzoxazin-4-ones（3a3d） were heated together with formamide to afford 2-substituted 6-methyl-4（3H）-quinazolinones（4a4d）,which were（converted） into the title compounds（5a5d） via brominating with N-bromosuccinimide in the presence of （PhCOO）2.The structures of all the intermediates and final products were confirmed with ESI-MS,1H NMR and elemental analysis.
基金Guizhou Province Natural Science United Fund(No.JLKK[2013]03 and LH[2015]7740)Guizhou Province Education Quality Promotion Engineering Project(No.KY[2014]228)
