Diisopropylethylamine → ethyl 4-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13 aR,13bR)-5a,5b,8,8,11a-pentamethyl-3a-((2-(4-(methylsulfonyl)piperazin-1-yl)ethyl)amino)-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)cyclohex-3-enecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a flask containing the crude ethyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(aziridin-1-yl)-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)cyclohex-3-enecarboxylate (0.094 g, 0.16 mmol), was added 1-Methanesulfonyl-piperazine (0.131 g, 0.800 mmol). The mixture was diluted with 1,4-dioxane (2 mL) and Hunig's base (0.168 mL, 0.960 mmol) was added. The mixture was attached to a reflux condensor and was heated to 100° C. for 24 h then was cooled to rt, concentrated under reduced pressure, and adsorbed to silica gel. The mixture was purified by flash chromatography using a 12 g silica gel column and a 20-80% ethyl acetate in hexanes gradient. The fractions containing the product were combined and concentrated under reduced pressure to give ethyl 4-((1R,3 aS,5aR,5bR,7aR,11aS,11bR,13 aR,13bR)-5a,5b,8,8,11a-pentamethyl-3a-((2-(4-(methylsulfonyl)piperazin-1-yl)ethyl)amino)-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)cyclohex-3-enecarboxylate as an off-white solid. LCMS: m/e 752.8 (M+H)+, 2.22 min (method 1).

Provenance & Evidence