2-(6-chloro-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-4-yl)acetic acid → 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(2-(7-chloro-2-oxo-2,4-dihydro-1H-benzo[d][1,3]oxazin-1-yl)acetamido)-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

The title compound was prepared in 36% 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-(6-chloro-3-oxo-2H-benzo[b][1,4]oxazin-4(3H)-yl)acetic acid was used instead of 3-(dimethylamino)propionic acid hydrochloride in Step 1. LCMS: m/e 653.5 (M+H)+, 2.29 min (method 6). 1H NMR (500 MHz, 1:1 CDCl3:MeOD) δ=7.92 (d, J=8.5 Hz, 2H), 7.21 (d, J=8.5 Hz, 2H), 7.05-7.01 (m, 1H), 7.01-6.97 (m, 2H), 6.83 (s, 1H), 5.29 (dd, J=1.7, 6.3 Hz, 1H), 4.73 (d, J=1.8 Hz, 1H), 4.70 (d, J=1.2 Hz, 2H), 4.66 (br. s., 1H), 4.63 (s, 1H), 4.57-4.50 (m, 1H), 2.65-2.57 (m, 1H), 2.51-2.34 (m, 2H), 2.13 (dd, J=6.4, 17.1 Hz, 1H), 1.96-1.85 (m, 1H), 1.83-1.72 (m, 3H), 1.70 (s, 3H), 1.69-1.64 (m, 1H), 1.63-1.55 (m, 2H), 1.54-1.45 (m, 4H), 1.45-1.30 (m, 5H), 1.30-1.23 (m, 1H), 1.18-1.12 (m, 2H), 1.10 (s, 3H), 1.02 (s, 6H), 0.95 (s, 3H), 0.94 (s, 3H).

Provenance & Evidence