Clonazepam → 11b-(2-chlorophenyl)-10-nitro-2,3,5,11b-tetrahydrooxazolo[3,2-d][1,4]benzodiazepin-6(7H)-one

Participants

Reaction Steps

A solution of 5.2 g of (0.02 M) of stannic chloride in 60 ml of dry ethylene dichloride under nitrogen was treated with 2.9 g (0.0091 M) of 5-(2-chlorophenyl)-1,3-dihydro-7-nitro-2H-1,4-benzodiazepin-2-one. The reaction was cooled in an ice bath, and 2.6 g (0.06 M) of ethylene oxide in 10 ml of ethylene dichloride was added with stirring over an 8 min period. After 18 hr at room temperature, the solution was made basic with concentrated ammonium hydroxide and filtered. The filtrates were washed with a saturated solution of brine, dried over anhydrous sodium sulfate and evaporated to dryness. The residue was crystallized from a mixture of dichloromethane, methanol and petroleum ether to give the above named product as white rods, melting at 201°-203°.

Provenance & Evidence