A solution of 3-(RS)-pyrrolidinyloxyamine dihydrochloride (III-c, Prepn. 3, 227 mg) and androstane-3,6,17-trione (495 mg) in THF: water (2/1, 27 mL) was stirred for 30 min. NaCl was added and stirred till the two phases separated. After extraction of the aqueous layer with THF, the combined organic phases were washed with brine, dried and evaporated. The crude was purified by flash chromatography (SiO2, CH2Cl2:MeOH:NH3 9:1:0.1). To the concentrated fractions 5M HCl in EtOAc was added. After dilution with Et2O, the solid was collected by filtration to give the title compound I-ac (464 mg, 60%). 1H-NMR (300 MHz, DMSO-d6, ppm from TMS): δ 9.59 (1H, bb), 9.41 (1H, bb), 4.74 (1H, m), 3.80-2.90 (5H, m), 2.60-1.20 (21H, m), 0.78 (6H, s).
