Abstract The intramolecular rearrangement of N-acyl-2-cyclopropylanilines by the action of protic acids gives substituted 4H-3, 1-benzoxazines. The reaction proceeds in high yield through the formation of benzoxazine precursors, namely, the corresponding 3, 1- benzoxazinium ions, which are stable in acid solution. N-Acylamino-2-alkenylbenzenes, in which the double bond of the alkyl chain is conjugated with the benzene ring, are capable ...
