Using Metal Indium Synthesis Of 2h-1, 4 - Benzo-oxazine Class Of Compounds

The application of benzoxazines is very extensive in polymer material and synthesis of medicinal substances, i. e. Most of them is synthesized from 2-aminophenol. To shorten the synthetic step of benzoxazines and provide more useful synthetic methods, the applicability of indium in the synthesis was studied in this work.To obtain starting materials of cyclization reactions, 2-(2-nitrophenoxyl)-1-arylethanones and ten it's derivatives were synthesized. We found out that the best condition is to make potassium carbonate,α-bromoacetophenone, 2-nirophenol dissolved in acetone and heated at reflux. And these compounds were identified with ¹H NMR.To synthesize 3-phenyl-2H-1, 4-benzoxazine, the reduction and intramolecular cyclization coditions of 2-(2-nitrophenoxyl)-1-phenylethanone were optimized. As a result, methanol was best reaction medium, reaction molar proportion of starting material, indium and acetic acid was 1:3:35, and the reaction was occurred under nitrogen gas protection. The reduction and intramolecular cyclization was simultaneously occurred in this condition.The ten 3-phenyl-2H-1, 4-benzoxazine derivatives were synthesized utilizing above reaction conditions, and the products were identified with ¹H NMR, ¹³C NMR and MS analytical techniques.