Diisopropylethylamine → tert-butyl 4-(2-(((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-9-(4-(methoxycarbonyl)phenyl)-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-3a-yl)amino)ethyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-((2-chloroethyl)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 (230 mg, 0.379 mmol), Hunig's Base (0.331 mL, 1.895 mmol) and tert-butyl piperazine-1-carboxylate (141 mg, 0.759 mmol) in DMSO (3 mL) was heated up at 120° C. for 1 hour. The reaction mixture was quenched with water (10 mL), extracted with ethyl acetate (3×8 mL), the extracts were combined, dried over sodium sulfate, filtered and concentrated under reduced pressure to provide the crude, the crude was purified by silica gel chromatography with 0-30% ethyl acetate/hexanes to provide the desired product as a white solid (150 mg, 52%). LCMS: m/e 756.66 (M+H)+, 2.50 min (method 11).

Provenance & Evidence