alpha-Hydroxyalprazolam → 6-phenyl-8-chloro-4H-s-triazolo[4,3-a][1,4]benzodiazepine-1-carboxaldehyde

참여 물질

반응 단계

A mixture of 1.3 g of 6-phenyl-8-chloro-4H-s-triazolo [4,3-a][1,4]benzodiazepine-1-methanol [cp., e.g. German `Offenlegungsschrift` No. 2,156,472, Belgian Pat. No. 775,558] , 3.4 g of manganese dioxide and 80 ml of benzene is refluxed for 2 hours. The reaction mixture is then filtered through a layer of silica gel, and the filtrate concentrated by evaporation. The residue is chromatographed through silica gel (Merck, 0.063 - 0.2 mm particle size) with various ethyl acetate/ethanol mixtures of increasing ethanol content as the eluant. The fractions eluted with ethyl acetate/ethanol (4:1) are combined and concentrated by evaporation. The residue is crystallised from ethyl acetate/petroleum ether to obtain 6-phenyl-8-chloro-4H-s-triazolo[4,3-a] [1,4]benzodiazepine-1-carboxaldehyde, M.P. 161°-163°.

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