Water → 2-Chloro-9,10-dihydro-9,10-methano-9-anthracenecarboxylic acid

Participants

Reaction Steps

To a cooled solution (0° C.) of 2-chloro-9-formyl-9,10-dihydro-9,10-methanoanthracene (described in example 1i) (20.0 g, 78.5 mmol) in acetone (260 mL) was added Jones reagent (24 mL; 27 g chromium trioxide, 23 mL water diluted up to 100 mL of reagent solution) in portions. The reagent was added until an orange color persists. The reaction, containing a significant amount of reduced chromium salts, was warmed to room temperature. The solvents were removed in vacuo and replaced with water (300 mL) saturated with sodium chloride. The aqueous phase was extracted with ethyl acetate (3×300 mL). Combined organic extracts were extracted with 2.5N NaOH (3×400 mL). The basic aqueous extracts were acidified with 3N HCl, saturated with sodium chloride, and extracted with ethyl acetate (4×300 mL). Combined organic extracts were dried over anhydrous magnesium sulfate, filtered, and reduced to a off-white solid. The procedure yielded 26.66 g (quantitative) of the title compound. No additional purification was required. 1H NMR (D6 -DMSO, 300 MHz) 13.2 (downfield) 7.46 (br s, 1H), 7.36 (m, 3H), 7.02 (m, 3 H), 4.45 (s, 1H), 2.67 (s, 2H) MS (CI, CH4) m/z 271 (M+1,100), 273 (34), 299 (M+29, 17), 253 (33), 243 (22), 227 (20)

Provenance & Evidence