Benzophenone → 2-(2',6'-Dimethyl-4'-t-butylphenyl)-5,5-dimethyl-1,3-cyclohexanedione

Participants

Reaction Steps

A solution of 7.00 g (0.042 mol) of 2-diazo-5,5-dimethylcyclohexane-1,3-dione in 300 ml of 5-t-butyl-m-xylene and 250 ml chlorobenzene containing 38.38 g (0.21 mol) of benzophenone was irradiated overnight with a 200 watt mercury arc lamp fitted with a borosilicate glass filter after degassing for 1 hour under nitrogen. The photolysis mixture was extracted with 0.25 N NaOH, washed with ether, acidified with 1 N HCl, and extracted with chloroform. The chloroform was dried over anhydrous MgSO4 and stripped to give a crude yellow solid. The photolysis was repeated and the combined crude product from these ractions was chromatographed through silica gel (0.063-0.2 mm) using benzene-ethyl acetate. The solid obtained from the chromatography was recrystallized from benzene to give 2.76 g (11%) of 2-(2',6'-dimethyl-4'-t-butylphenyl)-5,5-dimethyl-1,3-cyclohexanedione as white crystals, mp 224°-49° C.

Provenance & Evidence