Reaction Steps
The title compound was prepared in 31% yield from methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-amino-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 following the same procedure as described for the preparation of 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(3-(dimethylamino)propanamido)-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, except 2-(thiophene-2-sulfonamido)acetic acid was used instead of 3-(dimethylamino)propionic acid hydrochloride in Step 1. LCMS: m/e 733.6 (M+H)+, 2.06 min (method 6). 1H NMR (500 MHz, 1:1 CDCl3:MeOD) δ=7.92 (d, J=8.5 Hz, 2H), 7.73 (dd, J=1.4, 5.0 Hz, 1H), 7.66 (dd, J=1.2, 3.7 Hz, 1H), 7.20 (d, J=8.2 Hz, 2H), 7.16 (dd, J=3.8, 5.0 Hz, 1H), 6.88 (s, 1H), 5.32-5.26 (m, 1H), 4.78 (d, J=1.5 Hz, 1H), 3.58-3.45 (m, 2H), 2.63-2.57 (m, 1H), 2.56-2.50 (m, 1H), 2.42 (dd, J=8.2, 12.2 Hz, 1H), 2.13 (dd, J=6.3, 17.2 Hz, 1H), 1.98-1.88 (m, 1H), 1.87-1.76 (m, 2H), 1.73 (br. s., 1H), 1.72 (s, 3H), 1.70-1.66 (m, 1H), 1.63-1.53 (m, 3H), 1.53-1.46 (m, 4H), 1.45-1.37 (m, 3H), 1.37-1.30 (m, 2H), 1.28-1.22 (m, 1H), 1.14 (s, 3H), 1.10 (d, J=3.1 Hz, 1H), 1.03 (s, 3H), 1.02 (s, 3H), 0.94 (s, 3H), 0.94 (br. s., 3H).
