Methylhydrazine → 3-methyl-3H-benzo[d][1,2]diazepin-4(5H)-one

Participants

Reaction Steps

To a solution of o-formylphenylacetic acid (10 g, 61 mmol) (Bleasdale et al., J. Chem. Soc. Perkin Trans. I 1991, 1683) in 60 mL of EtOH was added N-methylhydrazine (4.2 g, 91 mmol) and refluxed for 1 h. The reaction mixture cooled, solvent removed and transferred the crude reaction mixture to a vaccum sublimation apparatus. The imine was heated at 140° C. under high vaccum for 1 h and collected the cyclized product by extracting with hot 20% ethyl acetate in hexane (Nagarajan et al., J. Med. Chem., 1972, 15(10), 1091). The product was crystallized from 20% ethyl acetate in hexane. 4,5-dihydro-3-methyl-3H-2,3-benzodiazepin-4-one was obtained in 50% yield.

Provenance & Evidence