Benzoylhydrazine → 1-Phenyl-4h-[1,2,4]triazolo[4,3-a][1,5]benzodiazepin-5(6h)-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-ethoxy-1,3-dihydro-benzo[b][1,4]diazepin-2-one (Preparation 3(A) (5 g, 24 mmol) in glacial AcOH (75 mL) was added benzoic acid hydrazide (3.33 g, 24.5 mmol). The reaction mixture was heated to 120° C. for 2 hours and was cooled to room temperature. The solvent was removed in vacuo by azeotropic distillation with heptane (2×). The residue was dissolved in a minimum amount of methylene chloride and 50 mL ethyl acetate and the solution was poured slowly with stirring into a solution of 100 mL saturated NaHCO3/100 mL water. Ether (150 mL) was added and the mixture was stirred for 5 minutes. The precipitate was collected by filtration, was washed with water and the minimum amount of ether to give 5.89 g of 1-phenyl-4H,6H-2,3,6,10b-tetraaza-benzo[e]azulen-5-one. 1H NMR (CDCl3) δ 9.02 (br s, 1H), 7.48-7.36 (m, 6H), 7.10 (t, 1H), 6.95 (d, 1H), 4.23 (d, 1H), 3.60 (d, 1H); MS 277 (M+1).

Provenance & Evidence