Trifluoroacetic acid → 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(dimethylamino)ethylamino)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)benzoic acid

Participants

Reaction Steps

A solution of tert-butyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-(dimethylamino)ethylamino)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 (59 mg, 0.088 mmol) in DCM (2 ml) was treated with TFA (0.6 ml, 7.6 mmol) and the mixture was stirred at rt for 12 h. The solvent was removed in vacuo to provide the title compound as a white solid (40 mg, 0.065 mmol, 74.0% yield). LCMS: m/e 615.7 (M+H)+, 2.00 min (method 7). 1H NMR (400 MHz, MeOD) δ ppm 7.94 (d, J=8.3 Hz, 2H), 7.24 (d, J=8.0 Hz, 2H), 5.33 (d, J=4.8 Hz, 1H), 4.78 (s, 1H), 4.67 (s, 1H), 3.73-3.42 (m, 4H), 3.33 (m, 1H), 2.99-2.94 (m, 1H), 2.93 (s, 6H), 2.53 (td, J=10.6, 5.6 Hz, 1H), 2.99-1.29 (m, 2H), 1.98-1.22 (m, 20H), 1.76 (s, 3H), 1.20 (s, 3H), 1.10 (s, 3H), 1.06 (s, 3H), 0.99 (s, 3H), 0.98 (s, 3H).

Provenance & Evidence