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 0.25N NaOH, washed with ether, acidified with 1N 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 reactions 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 244°-49° C.

Provenance & Evidence