Hydrochloric Acid → HCID 10470453, compound

Participants

Reaction Conditions

Reaction Steps

236 Grams (1 mol) of p-dibromobenzene and 1 l of dry toluene were introduced into a three-neck flask in dry nitrogen atmosphere to carry out dissolution with stirring at 50° C. To the resulting solution was dropwise added 525 ml of a hexane solution of 1.67 N commercial n-butyllithium (0.88 mol), over 30 minutes. After dropping, the temperature was maintained at 50° C. further for 30 minutes, and then lowered down to 25° C. To this solution was dropwise added a solution obtained by dissolving 135 g (0.8 mol) of 4-n-pentylcyclohexanone in 125 ml of toluene, over 30 minutes, followed by continuing stirring for 30 minutes at 30° C., and then 250 ml of 6 N hydrochloric acid was added dropwise while maintaining the temperature at 30° C. or lower (the first step). The resulting organic layer was separated, 25 g of potassium hydrogen sulfate was added thereto, and after hexane was distilled off with stirring, the resulting residue was concentrated until the liquid temperature reached 110° C. to complete the dehydration reaction (the second step). The resulting concentrate was distilled under a reduced pressure to take a fraction of 160°~170° C./1 mm Hg, whereby there was obtained 160 g of 1-(p-bromophenyl)-4-n-pentylcyclohexene (R=n-C5H11 and n=1 in said formula (B)) (yield: 62.4%), which was then twice recrystallized from ethanol to give a crystal having a melting point of 67°~68° C.

Provenance & Evidence