1,2-Dichloro-4-nitrobenzene → 2-(2'-Chloro-4'-nitrophenyl)-5,5-dimethyl-1,3-cyclohexandione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution containing 42.05 g (0.300 mol) of 5,5-dimethyl-1,3-cyclohexanedione and 100 g (0.718 g-atom) of anhydrous potassium carbonate in 300 ml of dry dimethylformamide was heated to 75° C. under nitrogen and stirred for one hour. The 3,4-dichloronitrobenzene, 57.60 g (0.300 mol) was dissolved in 100 ml dimethylformamide and added dropwise to the reaction mixture while stirring and maintaining the temperature of the reaction mixture at 75° C. A deep red-colored solution formed, and when the addition was complete the reaction temperature was raised to 100° C. and held at this temperature for 3 hours. Most of the dimethylformamide was removed by vacuum distillation. The residue was poured into 21 of ice water and extracted three times with 500 ml of benzene. Nitrogen was then passed through the aqueous solution while warming to remove dissolved benzene. The aqueous solution was cooled in an ice bath and acidified to give a tacky precipitate, which, upon warming solidified and was collected by suction filtration. The product was recrystallized from acetone to give 31.7 g (36%) of 2-(2'-Chloro-4'-nitrophenyl)-5,5-dimethyl-1, 3-cyclohexanedione as a white powder, m.p. 250°-253° C.

Herkunft & Nachweise