p-Toluenesulfonic acid → Alprazolam

Participants

Reaction Steps

To a solution of 2.84 parts of 7-chloro-2-hydrazino-5-phenyl-3-H-1,4-benzodiazepine in 50 parts by volume of chloroform are added 10 parts of ethyl orthoacetate and 4 parts of p-toluenesulfonic acid. The solution is left standing at room temperature for 6 hours and heated for a while on a water-bath to complete the reaction. The mixture is washed with saturated aqueous sodium bicarbonate, then with water and dried over anhydrous sodium sulfate. After evaporation of the solvent, the residue is treated in a similar manner to Example 18 to give 8-chloro-1-methyl-6-phenyl-4H-s-triazolo [4,3-a][1,4] benzodiazepine as colorless needles. Melting point: 224° C to 225° C.

Provenance & Evidence