Hydrochloric Acid → 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)-2-fluorobenzoate dihydrochloride

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Reaction Steps

To a solution of crude methyl 2-fluoro-4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-isocyanato-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 (2.93 g, 4.99 mmol) in THF (35 mL) was added 12N HCl (10 mL, 121 mmol). After stirring the mixture for 24 h, the mixture was diluted with water (100 mL) until solids precipitated. The solids were collected by filtration and were washed with water to afford the title compound (2.75 g, 4.33 mmol, 87% yield), as an off-white solid that was used in the next step with no additional purification. LCMS: m/e 562 (M+H)+, 1.96 min (method 2).

Provenance & Evidence