1128-22-9Relevant articles and documents
3,4-Dihydro-benzoxazine Derivatives from 2-Acyl(or aroyl)cyanatobenzenes
Buttke, K.,Ramm, M.,Niclas, H.-J.
, p. 544 - 548 (2007/10/02)
3,4-Dihydro-2H-benzoxazin-2-ones 3 are obtained from 2-acyl(or aroyl)-cyanatobenzenes 2 and anisole.The reaction proceeds under Friedel-Crafts conditions via DIMROTH rearrangement.Compounds 2, dissolved in diethyl ether, react with 1 in the presence of finely powdered KOH at ambient temperature leading to 8.The structure of 8b is confirmed by X-ray structure analysis. (Z)-4-Ethylidene-3,4-dihydro-2H-benzoxazin-2-one 9 is formed upon treatment of 2-cyanatopropiophenone 2b with diluted hydrochloric acid.The ethylene derivative 5 is obtained from 4 upon reaction with cyanogen bromide/triethyl amine.