Trifluoroacetic acid → HCID 57941426, compound

Participants

Reaction Conditions

Reaction Steps

Trifluoroacetic acid (15 mL) was added to a cooled (0° C.) solution of crude N′-(4-methoxy-phenyl)-N′-((1R,4R)-4,7,7-trimethyl-3-oxo-bicyclo[2.2.1]heptane-2-carbonyl)-hydrazinecarboxylic acid tert-butyl ester (˜18.5 mmol) in dichloromethane (15 mL), and the solution was stirred at ˜0° C. for 15 min and then at room temperature for 2.5 h. The solvent was evaporated and the residue was dissolved in dichloromethane (150 mL) and washed with water (4×250 mL) until the pH of the aqueous washing was ˜5. The organic layer was washed with brine (150 mL), dried (magnesium sulfate), and then the flask was wrapped in aluminum and stored in a freezer overnight. The magnesium sulfate was filtered off, and the solvent was evaporated to give an orange/red semi-solid which was triturated with 10% dichloromethane/hexanes, filtered, and washed with hexanes. The solid was crushed, washed again with hexanes, and then dried under vacuum to give (4S,7R)-2-(4-methoxy-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (3.95 g, 72%) as a tan solid.

Provenance & Evidence