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
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
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)
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.
基金Financial support was provided by the NSFC (No.21202136)the Young Teachers Program and the Start-up Foundation of Hubei University of Technology and Science (No.KY13040 and KB1008,respectively)
