Nitrogen → 8-Nitro-1,3,4,5-tetrahydro-2H-1-benzazepin-2-one

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Reaction Conditions

Reaction Steps

7.87 g of 7-nitro-1-tetralone from step A were placed in 55 ml of AcOH. Next, 7.0 g of NaN3 were added and the resulting mixture was heated to 60° C. Then, 10.3 ml of conc. H2SO4 were slowly added dropwise. N2 evolution took place and the temperature rose to 90° C. The reaction mixture was held at this temperature for 1/2 hour, then cooled and poured cautiously into an ice/28% NaOH solution. The mixture was extracted thoroughly with AcOEt, washed with a small amount of water, dried and evaporated. Flash chromatography on SiO2 (hexane/ethyl acetate (1/1→pure ethyl acetate)) yielded 2.58 g of 2,3,4,5-tetrahydro-8-nitro-2-oxo-1H-1-benzazepine as brown crystals of m.p. 224°-226° C. besides regioisomeric lactam and unreacted starting material.

Provenance & Evidence