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 (300.0 g, 797 mmol.) and anhydrous ethanol (15 L, denatured with toluene) to a 22 L flask equipped with overhead agitation, heating mantle, and condenser. Heat the slurry to about 75° C. to provide a homogeneous solution. Add a solution of 1 M aqueous phosphoric acid (877 mL, 877 mmol, 1.1 equiv) over 10 minutes while maintaining the temperature above 72° C. The salt may begin precipitating after approximately 380 mL of phosphoric acid solution is added. Remove the heating mantle after the addition is complete, and allow the slurry to cool to about 22° C. Cool the slurry to about 5° C. and stir for about 2 hours. Filter the mixture and wash the cake three times with 500 mL cold ethanol. Dry the solid overnight in a vacuum oven at about 50° C. to provide 370 g (98% yield) of the title crystal form as a white solid.

Provenance & Evidence