Methyl iodide → (+)-5-(o-chlorophenyl)--1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one

Participants

Reaction Steps

105.7 g (0.32 mol) of crude rac-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one, dissolved in 1 liter of acetone, are treated with 88.6 g (0.64 mol) of potassium carbonate and 39.9 ml (0.64 mol) of methyl iodide and the mixture is stirred at room temperature for 22 hours. The mixture is evaporated to dryness and the residue is taken up in methylene chloride. The organic phase is washed with water, dried and evaporated. Recrystallisation of the residue from methylene chloride/ethanol gives rac-5-(o-chlorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one of melting point 170°-174° C.

Provenance & Evidence