Water → 7-Chloro-1-(2,3-dihydroxypropyl)-5-(o-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one

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Reaction Steps

A solution of 16 g of potassium permanganate in 300 ml of water was added dropwise within 15 minutes at 10°C to a solution of 33.0 g of 1-allyl-7-chloro-5-(2-fluorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one in 300 ml of acetone. After the potassium permanganate addition, the solution is stirred for a further 10 minutes. Then the mixture is filtered off by vacuum from the precipitated manganese dioxide and the manganese dioxide is washed with acetone. Subsequently the acetone is distilled off on a rotary evaporator. The remaining aqueous phase is extracted with ethyl acetate; the ethyl acetate solution is washed with saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated. The residue is chromatographed on silica gel with ethyl acetate/methanol (9:1). The pure fractions are combined and evaporated. Crystallization from ethyl acetate yields pure 7-chloro-1-(2,3-dihydroxypropyl)-5-(2-fluorophenyl) -1,3-dihydro-2H-1,4-benzodiazepin-2-one of melting point 117°-118°C.

Provenance & Evidence