Into 50 ml. of chloroform, 280 mg. of Geldanamycin was dissolved and then, 1 ml. of n-propylamine was added. The mixture was stirred at room temperature for 1 hour and the mixture was charged into 50 ml. of cold water and then, pH was adjusted 3 with 6 N-HCl. The chloroform layer was separated and the water layer was extructed with 50 ml. of chloroform. Both chloroform layers were combined and dehydrated over anhydrous sodium sulfate for 2 hours. Chloroform was distilled off under a reduced pressure to remain a reddish violet solid product. The solid product was recrystallized from acetone-n-hexane to obtain 286 mg. (yield 98%) of 17-n-propylamino-Geldanamycin as reddish violet acicular crystal.
