Sulfuric Acid → Methyl 2-oxo-2,3,4,5-tetrahydro-1H-benz[b]azepine-9-carboxylate

Participants

Reaction Conditions

Reaction Steps

Conc. H2SO4 is added dropwise at 0° C. to a solution of 3.040 g of methyl 8-oxo-5,6,7,8-tetrahydronaphthalene-1-carboxylate in 550 ml of chloroform, in the course of which the temperature is kept at 0-3° C. On completion of addition, the reaction solution is warmed to 10° C. and 21.80 g of sodium azide are added in portions over the course of 45 minutes. The reaction mixture is subsequently stirred at 50° C. over 2.5 hours. The reaction mixture is cooled to room temperature and subsequently poured onto a mixture of 200 g of potassium carbonate, 1000 ml of water and 400 g of ice. The mixture is made basic with 44 ml of 50% KOH and extracted with 2×500 ml of dichloromethane. The combined organic phases are washed with 1000 ml of water and concentrated. The title compound is obtained as a reddish solid from the residue by means of flash chromatography (SiO2 60F). Rf=0.25 (1:1 EtOAc-heptane); Rt=3.38.

Provenance & Evidence