Hydrochloric Acid → HCID 13281346, compound

Participants

Reaction Steps

Under a dry nitrogen atmosphere a solution of the oil just described (3.0 g), potassium hydroxide (7.2 g, 0.128 mole), ethylene glycol (30 ml) and water (30 ml) was heated at reflux for 24 hours. The reaction mixture was cooled to room temperature and transferred to a separatory funnel. The reaction flask was washed successively with water (150 ml), diethyl ether (150 ml), 2N hydrochloric acid (150 ml) and the washes added to the separatory funnel. Ice was added to the separatory funnel. The contents of the separatory funnel were made acidic with concentrated hydrochloric acid, then shaken well. A white solid formed, was removed from the mixture by filtration and found to be 5,6,7,8-tetrahydrodibenzo[a,c]cycloocten-4-carboxamide (compound A). An aqueous phase was separated from the filtrate and extracted with diethyl ether (three 100 ml portions) (Extracts B). The extracts (Extracts B) were combined and evaporated under reduced pressure to leave a solid. The solid was dissolved in methylene chloride (200 ml) and the solution (Solution C) washed with 2N sodium hydroxide (two 125 ml portions) (basic washes D). The basic washes (basic washes D) were combined and back washed with methylene chloride (100 ml) (organic wash E, basic aqueous phase F). The organic phases (solution C, wash E) were combined, dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated under reduced pressure to yield a solid which consisted of 5,6,7,8-tetrahydrodibenzo[a,c]cycloocten-4-carboxamide and 5,6,7,8-tetrahydrodibenzo[a,c]cycloocten-4-carbonitrile (compound G). The basic aqueous phase (basic aqueous phase F) was acidified with concentrated hydrochloric acid and the solution saturated with sodium chloride. The saturated solution was extracted with diethyl ether (two 200 ml portions). The extracts were combined, dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to yield a small amount of 5,6,7,8-tetrahydrodibenzo[a,c]cycloocten-4-carboxylic acid. All portions of carbonitrile and carboxamide, which were isolated above (compounds A, G) were combined and treated with potassium hydroxide (7.7 g) and ethylene glycol (50 ml) at 150° for approximately 18 hours. The reaction mixture was cooled to room temperature, transferred to a separatory funnel and treated as above. After the contents of the separatory funnel were acidified and shaken, the aqueous phase was separated from the mixture. The aqueous phase was extracted with diethyl ether and evaporated under reduced pressure to leave a residue. The residue was dissolved in methylene chloride and the solution extracted with 2N sodium hydroxide. The aqueous extract was washed with methylene chloride, then acidified with concentrated hydrochloric acid and saturated with sodium chloride. The saturated solution was extracted with diethyl ether. The extract was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to give 5,6,7,8-tetrahydrodibenzo[a,c]cycloocten-4-carboxylic acid as a solid (1.7 g) (m.p. 178°-180°). The IR and nmr spectra were consistent with the proposed structure.

Provenance & Evidence