HALAZEPAM

Originator

Paxipam,Schering,US,1981

The Uses of HALAZEPAM

Sedativehypnotic.

Manufacturing Process

Prepare a solution of sodium methylate by dissolving 3.9 g of sodium metal in 500 ml of methanol. Add 39.0 g of 7-chloro-1,3-dihydro-5-phenyl-2H-1,4- benzodiazepine-2-one. Evaporate the reaction mixture to a residue and dissolve the residue in 170 ml of dimethylformamide. Add 30 g of 2,2,2- trifluoroethyl iodide and stir at room temperature for ? hour, then heat to 60°C to 70°C for an additional 7 hours. Add 19 g of 2,2,2-trifluoroethyl iodide and resume the heating and stirring at 60°C to 70°C for an additional 16 hours. Filter off the solids and evaporate the filtrate to a residue in vacuo. Triturate the residue with water and extract with ethyl ether. Wash the ethereal extract with water, dry over anhydrous sodium sulfate and evaporate the solvent to a residue. Extract the residue with ethyl ether and filter. Concentrate the ethereal extract to a residue. Dissolve the residue in benzene and chromatograph on 300 g of alumina contained in a glass column 1.5 inches in diameter to give the crude product. Elute with benzene. Crystallize this product from acetone-petroleum ether to obtain the product.

brand name

Paxipam (Schering).

Therapeutic Function

Tranquilizer

General Description

Halazepam, 7-chloro-1,3-dihydro-5-phenyl-1(2,2,2-trifluoroethyl)-2H-1,4-benzodiazepine-2-one(Paxipam), is marketed as an anxiolytic and well absorbed. Itis active and present in plasma, but much of its activity iscaused by the major active metabolites nordazepam andoxazepam.