Acetic Acid → (S)-5-(o-chlorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one

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Reaction Steps

100 g (0.3 mol) of (S)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one are dissolved in 700 ml of dry acetone. The solution is treated with 79 ml of ground potassium carbonate and with 31.4 ml of methyl iodide and the mixture is stirred at room temperature for 4 hours. The mixture is treated with 30 ml of glacial acetic acid and evaporated. The residue is treated with an ice/water mixture and extracted several times with methylene chloride. The organic phase is washed with water, dried over sodium sulphate, concentrated and treated with methanol. After filtering off the separated crystals, there is obtained (S)-5-(o-chlorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one of melting point 159°; [α]25D =+381.2° (1 percent solution in methylene chloride).

Provenance & Evidence