Benzoylhydrazine → 8,9-difluoro-1-phenyl-4H,6H-2,3,6,10b-tetraaza-benzo[e]azulen-5-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-ethoxy-7,8-difluoro-1,3-dihydro-benzo[b][1,4]diazepin-2-one (Preparation 3(B) (5.38 g, 22.4 mmol) in acetic acid (100 mL) was added benzoic hydrazide (3.11 g, 22.85 mmol). The reaction was heated to 120° C. for 18 hours and the volatiles were concentrated in vacuo. The residue was dissolved in CH2Cl2 and the organic solution was washed with aqueous NaHCO3 (1×), dried (Na2SO4), filtered and concentrated. The solid residue was triturated with a warm mixture of EtOAc and hexanes and was filtered. The solids were triturated in 50% hexanes in Et2O and filtered to provide 3.97 g of 8,9-difluoro-1-phenyl-4H,6H-2,3,6,10b-tetraaza-benzo[e]azulen-5-one. 1H NMR (DMSO-d6) δ 7.52-7.36 (m, 6H), 7.06 (m, 1H), 3.91 (d, 1H), 3.76 (d, 1H); MS 313.1 (M+1), 311.1 (M−1).

Provenance & Evidence