Convenient synthesis of -alkyl-3,1-benzoxazin-2-ones from carbamate protected anthranil aldehydes and ketones one-step alkylation/alkoxy rearrangement

A practical and step-economical protocol was developed to prepare N -alkyl-3,1-benzoxazin-2-one derivatives from anthranil aldehydes and ketones via one-step alkylation/alkoxy rearrangement, where three new chemical bonds and one ring were constructed in a single step. Control studies revealed a stepwise mechanism and that the alkoxy rearrangement was an intermolecular process. A new straightforward protocol was developed to synthesize N -alkyl-3,1-benzoxazin-2-one derivatives in one step, where 3 chemical bonds and 1 ring were constructed cooperatively.