Phosphoric Acid → (3-cyano-1H-indol-7-yl)-[4-(4-fluorophenethyl)piperazin-1-yl]-methanone phosphate hydrate

Participants

Reaction Conditions

Reaction Steps

Add (3-cyano-1H-indol-7-yl)-[4-(4-fluorophenethyl)piperazin-1-yl]methanone (1.00 g, 2.66 mmol) and anhydrous ethanol (50 mL) to a flask equipped with a magnetic stir bar, heating mantle, and condenser. Heat the slurry to 65° C. to provide a homogeneous solution. Add a solution of 1 M aqueous phosphoric acid (4 mL, 4 mmol, 1.5 equiv) over 1 minute while maintaining the temperature above 60° C. Remove the heating mantle after the addition is complete, and allow the solution to cool to about 22° C. Precipitate may begin to form when the temperature reaches about 53° C. Stir the slurry for 2.5 hours at about 22° C. Filter the mixture and wash the cake with 5 mL, then 10 mL of ethanol. Dry the solid overnight in a vacuum oven at 50° C. to provide 1.23 g (98% yield) of the title crystal form as a white solid.

Provenance & Evidence