Hydrochloric Acid → Topotecan Hydrochloride

Participants

Reaction Conditions

Reaction Steps

8.7 L of water and 78 ml of 0.1 N hydrochloric acid were charged into a reactor and stirred for 15 minutes. 250 g of topotecan acetate prepared according to Example 2 was charged into the above reactor and stirred for 15 minutes. The obtained solution was filtered through a 0.22-micron filter. The filtrate and 8.8 L of isopropyl alcohol were charged into a flask and concentrated at 35.8° C. under a vacuum of −0.95 Kg/cm2 until 5 L of the solvent remained (distillate quantity 10.5 L). Then the reaction mass was cooled to 27° C. and 50 L of acetone charged. The obtained suspension was stirred for 1 hour at 27° C. and then filtered. The flask was rinsed with 2 L of acetone and the wet solid was washed with the rinsing. The wet solid was suction dried for 30 minutes and then wet solid was suspended in 9 L of acetone in a reactor and stirred for 30 minutes at 26.8° C. The suspension was filtered and the reactor rinsed with 5 L of acetone. The wet solid was washed with the rinsing and then solid was suction dried for 30 minutes. The obtained wet solid was dried at 28° C. under a vacuum of 700 mm Hg for 5 hours with de-lumping of the solid every hour of the drying. Finally the resultant solid was dried at 48° C. under a vacuum of 700 mm Hg for 1 hour to afford 169 g of the title compound of Formula I.

Provenance & Evidence