Reaction Steps
To a solution of tert-butyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((3-(dimethylamino)propylamino)methyl)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (114 mg, 0.167 mmol) in DCM (1 ml) was added TFA (0.4 ml, 5.19 mmol). The mixture was stirred at rt for 5 h and was concentrated under reduced pressure. The residue was purified by prep HPLC. The fractions containing the expected product were combined and concentrated under reduced pressure to afford the title compound as a white solid (77 mg, 0.122 mmol, 73.3% yield). LCMS: m/e 629.6 (M−H)−, 2.22 min (method 6). 1H NMR (500 MHz, Acetic acid) δ ppm 8.03 (d, J=8.24 Hz, 2H) 7.30 (d, J=8.24 Hz, 2H), 5.37 (d, J=4.58 Hz, 1H), 4.79 (s, 1H), 4.68 (s, 1H), 3.32-3.44 (m, 3H), 3.25-3.32 (m, 2H), 2.96 (d, J=13.12 Hz, 1H), 2.89-2.94 (m, 6H), 2.49-2.58 (m, 1H), 2.30-2.38 (m, J=8.09, 7.86, 7.74, 7.74 Hz, 2H), 1.75 (s, 3H), 1.19 (s, 3H), 1.13-2.23 (m, 22H), 1.09 (s, 3H), 1.08 (s, 3H), 1.02 (s, 3H), 1.00 (s, 3H).
