Hydrogen Bromide → 1,3,4,5-tetrahydro-2H-dibenzo[2,3:6,7]thiepino[4,5-d]azepin-2-one

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Reaction Conditions

Reaction Steps

With stirring, 90 g (0.2 mole) of the above hydrobromide, 1.5 liters of dimethyl formamide and 1.3 liters of water are refluxed for 2 hours in a nitrogen atmosphere. The reaction mixture is then diluted with 800 ml of water at 90°-100° C. and then cooled with ice cooling to 5° C., when 1,5-dibenzo-2H-dibenzo[2,3:6,7]thiepino[4,5-d]azepine-2,4(3H)-dione crystallises out. The crystals are collected with suction and well washed with water and acetone. After drying at 100° C. under reduced pressure, the crude product melts at 253+-256° C. With stirring and while keeping the temperature at 20°-30° C., a suspension of 61.4 g (0.2 mole) of 1,5-dihydro-2H-dibenzo[2,3:6,7]thiepino[4,5-d]azepine-2,4(3H)-dione in 200 ml of abs. diethyl ether is added in a nitrogen atmosphere and in the course of 30 minutes to a suspension of 22.8 g (0.6 mole) of lithium aluminium hydride in 3.5 liters of abs. diethyl ether and 350 ml of abs. tetrahydrofuran. The reaction mixture is subsequently refluxed for 24 hours and then cooled to 0°-5° C. Excess lithium aluminium hydride is cautiously decomposed by the dropwise addition of 150 ml of ethyl acetate and then of 300 ml of water. The organic phase is separated, washed firstly with 2N hydrochloric acid and then repeatedly with water, dried over sodium sulphate and then completely evaporated to dryness, leaving as residue 1,3,4,5-tetrahydro-2H-dibenzo[2,3:6,7]thiepino[4,5-d]azepin-2-one with a melting point of 195°-198° C.

Provenance & Evidence