Hydrochloric Acid → HCID 57941325, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (1R,4R)-4,7,7-trimethyl-3-oxo-bicyclo[2.2.1]heptane-2-carboxylic acid ethyl ester (Intermediate 4; 5.00 g, 22.3 mmol) and 2,2,2-trifluoroethylhydrazine (70% in water; Aldrich; 25.00 g, 153 mmol) was heated in a sealed tube at 100° C. for 19 h. The reaction mixture was allowed to cool, and HCl in dioxane (4 M; 40 mL, 160 mmol) was added cautiously. The reaction mixture was heated again at 100° C. for 45 min, cooled to room temperature, and added to water (200 mL). The mixture was extracted with dichloromethane (3×150 mL). The combined organic layers were washed with brine (150 mL), dried (sodium sulfate), filtered, evaporated, purified by flash chromatography (20-50% ethyl acetate) to give (4S,7R)-7,8,8-trimethyl-2-(2,2,2-trifluoro-ethyl)-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (1.04 g, 17%) as a light orange solid.

Provenance & Evidence