p-Toluenesulfonic acid → Cyclohexanone, 3,3-dimethyl-

Participants

Reaction Conditions

Reaction Steps

312 mg of 5% Pd/C were placed in a 37 mL glass-liner. 4.38 g of dimedone (31 mmol), 7.8 g of isopropanol (10 mL) and 174 mg of p-toluene sulfonic acid (1 mmol) were added. The glass-liner was closed and stirring was started with 500 rpm. The autoclave was flushed three times with 5 bara N2. The stirrer was turned off. The autoclave was pressurized with 5 bara H2 for 10 minutes for pressure check. The pressure was released. The stirrer was turned on again to 500 rpm and the autoclave was heated to 85° C. internal temperature. The autoclave was pressurized with 2 bara H2 and the stirrer was set to 1000 rpm. The reaction mixture was stirred under 2 bara H2 at 85° C. for 2 hours and 50 minutes. Then stirring was slowed to 500 rpm, the autoclave was cooled to a temperature below 25° C. and depressurized. After three times flushing with N2 at 5 bara for 100 minutes stirring was stopped and the autoclave was opened. The content was sucked and filtrated over a 0.45 μm filter. A 30 mL filtrated sample was diluted with 1 mL of isopropanol and 5 mg of NaHCO3 and then analyzed by GC. The total yield of 3,3-dimethylcyclohexan-1-one was 97% with a selectivity of 97%.

Provenance & Evidence