A Convenient Method for the Synthesis of 1,5-benzodiazepin-2-one

New 3-hydroxy-1,5-benzodiazepin-2-ones were synthesized through condensation between o- phenylenediamines with glycidic ester. Alkylation and oxidation of some of the obtained compounds were also explored in different conditions yielding various oxidized and alkylated benzodiazepines. The structural elucidation of the synthe- sized compounds was achieved by MS, NMR spectroscopy and also through X-ray diffraction analysis. The glycidic ester was thus shown to be an interesting synthon in the synthesis of new 1,5-benzodiazepines used in alkylation and oxidation reactions. Synthesis of 3-hydroxy -4-phenyl tetrahydro-1,5- benzodiazepin-2-one (4) and (5) A mixture of o-phenylenediamine 1 or its dimethylated derivative 2 (0.03 mole) and ethyl glycidate (0.03 mole) was refluxed in 80 mL of xylene during 48 hours. The obtained crude mixture was left at room temperature during one night. The trans diastereoisomers 4a or 5a which precipitate were filtered under reduced pressure.