Water → 2-carbomethoxy-5-oxo-5H-dibenzo[a,d]cycloheptene

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Reaction Conditions

Reaction Steps

4.68 G of 2-carbomethoxy-5-oxo-5H-dibenzo[a,d]cycloheptane is refluxed in 100 ml. of carbon tetrachloride containing 3.56 g. (1 eq.) of N-bromosuccinimide while being irradiated with a 100 watt incandescent lamp. After 2 hours the solution is cooled, filtered and evaporated to dryness. The residue is dissolved in 30 ml. of dimethylformamide and 2.48 g. (1eq.) of diazabicylononene is added. The mixture is heated briefly to 60° C, and water and ethyl acetate are added. The organic layer is washed with dilute hydrochloric acid and water, then dried and evaporated to give 2-carbomethoxy-5-oxo-5H-dibenzo[a,d]cycloheptene. Hydrolysis is eight to one aqueous methanol, 5% potassium hydroxide, followed by acidification with dilute hydrochloric acid yields 5-oxo-5H-dibenzo[a,d]cycloheptene-2-carboxylic acid (m.p. 261°-262° C).

Provenance & Evidence