alpha-Hydroxytriazolam → 6-(o-chlorophenyl)-8-chloro-4H-s-triazolo[4,3-a][1,4] benzodiazepine-1-carboxaldehyde

Beteiligte Stoffe

Reaktionsschritte

A suspension of 1.3 g of 6-(o-chlorophenyl)-8-chloro-4H-s-triazolo[4,3-a][1,4]benzodiazepine-1-methanol and 3.4 g of manganese dioxide in 200 ml of benzene is refluxed for 2 hours. The reaction mixture is then filtered and the filtrate concentrated by evaporation. The resulting foam is dissolved in a little ethyl acetate and the solution chromatographed on ca. 60 g of silica gel (Merck, 0.063 - 0.2 mm particle size) with ethyl acetate as the eluant. Fractions each of ca. 80 ml are collected. The fractions 4-8 are combined, concentrated by evaporation, and the residue crystallised from an ethyl acetate/ether/petroleum ether mixture to obtain 6-(o-chlorophenyl)-8-chloro-4H-s-triazolo[4,3-a][1,4] benzodiazepine-1-carboxaldehyde, M.P. 182°-189°.

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