Reaction Steps
To a solution of methyl 4-[(1S,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-[[2-(1,1-dioxo-1,4-thiazinan-4-yl)acetyl]amino]-1-isopropyl-5a,5b,8,8,11a-pentamethyl-1,2,3,4,5,6,7,7a,11,11b,12,13,13a,13b-tetradecahydrocyclopenta[a]chrysen-9-yl]benzoate, TFA (33 mg, 0.040 mmol) in THF (Volume: 3 mL) was added a 0.753 molar solution of lithium hydroxide monohydrate (0.316 mL, 0.158 mmol) in H2O. The reaction mixture was heated to 75° C. After 5.5 h, the reaction was concentrated to dryness. The crude residue was dissolved in THF (1.2 mL), MeOH (0.3 mL) and 1N HCl (0.2 mL). The solution was filtered and injected into reverse phase HPLC for purification using HPLC method 3 to give 4-((1S,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(((1,1-dioxido-4-thiomorpholinyl)acetyl)amino)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-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, TFA (17.9 mg, 0.021 mmol, 54.1% yield) as a white solid. LCMS: m/z 707.6 (M+H+), retention time 2.030 min (method 6). 1H NMR (500 MHz, METHANOL-d4) δ=7.93 (d, J=8.5 Hz, 2H), 7.21 (d, J=8.5 Hz, 2H), 7.13 (s, 1H), 5.31 (dd, J=1.5, 6.1 Hz, 1H), 3.26-3.22 (m, 5H), 3.21-3.15 (m, 4H), 2.66-2.59 (m, 1H), 2.37 (dd, J=6.7, 12.5 Hz, 1H), 2.17 (dd, J=6.4, 17.1 Hz, 1H), 1.99-1.91 (m, 1H), 1.80-1.70 (m, 4H), 1.67-1.57 (m, 2H), 1.57-1.45 (m, 9H), 1.44-1.39 (m, 1H), 1.39-1.26 (m, 3H), 1.18-1.11 (m, 2H), 1.09 (s, 3H), 1.04 (s, 6H), 0.96 (s, 3H), 0.95 (s, 3H), 0.91 (d, J=7.0 Hz, 3H), 0.82 (d, J=6.7 Hz, 3H).
