Alprazolam → U 43465F

Participants

Reaction Steps

A stirred solution of N,N,N',N'-tetramethyldiaminomethane (2.244 g., 0.022 mole) in dry dimethylformamide (50 ml.) was cooled in an ice bath and treated dropwise with acetyl chloride (1.65 ml., 0.023 mole). The ice bath was removed and the mixture was kept at 25° for 45 min. and treated with 8-chloro-1-methyl-6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine (3.09 g., 0.01 mole). After 30 min. the mixture was poured into ice water, made alkaline with sodium bicarbonate, saturated with sodium chloride and extracted with chloroform. The extract was washed with a dilute salt solution, dried over anhydrous sodium sulfate and concentrated in vacuo using xylene and toluene to help remove residual dimethylformamide. A solution of the residue in ethanol was acidified with a solution of one equivalent of p-toluenesulfonic acid in ethanol and crystallized to give 8-chloro-1-[2-(dimethylamino)ethyl]-6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine p-toluenesulfonate in three crops; 2.69 g. of melting point 195°-196° C.; 0.751 g. of melting point 192°-195.5° C. and 0.033 g. of melting point 195°-197° C. The total yield was 64.6%.

Provenance & Evidence