Methanol → Methyl 2,3,4,5-tetrahydro-7-iodo-4-methyl-3-oxo-1H-1,4-benzodiazepine-2-acetate

Participants

Reaction Conditions

Reaction Steps

Methyl 2,3,4,5-tetrahydro-3-oxo-4-methyl-1H-1,4-benzodiazepine-2-acetate (80 g, 0.32 mole) was added to CH2Cl2 (400 ml) and MeOH (400 ml). The mixture was heated at 40° C. for 0.5 hr then cooled to 25° C. Pyridine iodine monochloride complex was added in portions (82g, 0.51 mole). After the addition, the reaction was stirred for 10 minutes then CH2Cl2 (400 ml) added. The reaction mixture was stirred for 1.0 hr then washed with sodium metabisulphite solution (5 g+400 ml water), followed by water (400 ml). The temperature was maintained at 30° C. during the washing process. CH2Cl2 (450 ml) was replaced with 60/80 petrol (450 ml by ‘put and take’ distillation. A further portion of CH2Cl2 (200 ml) was replaced with 60/80 petrol, the mixture cooled slowly to 10° C., and the product filtered off and washed with 60/80 petrol. The product was dried in vacuo to yield the title compound (108 g, 92%).

Provenance & Evidence