Hydrogen Peroxide → Adipic Acid

Participants

Reaction Steps

To a mixture of [Mn2O3(Me3-TACN)2] (PF6)2.H2O (16.2 mg, 20 μmol, 0.2 mol %) and 2,6-dichlorobenzoic acid (57.3 mg, 0.30 mmol, 3.0 mol %) in CH3CN (7 ml) was added H2O2 (30 μl of a 50% aq. solution, 0.53 mmol) at room temperature and the resulting mixture was stirred for 20 min. Subsequently cyclohexene (0.805 g, 9.70 mmol) was added together with CH3CN (2 ml) and water (1 ml). H2O2 (5.67 ml of a 50% aq. solution, 100 mmol, 10.0 equiv.) was then added at 60° C. using a syringe pump (0.7 ml/h). New batches of [Mn2O3(Me3-TACN)2] (PF6)2.H2O (16.2 mg, 20 μmol, 0.2 mol % per batch) were added to the reaction mixture 1.5, 3.5, 5 and 7 hours after the addition of H2O2 had commenced. When the addition of H2O2 was completed, the mixture was stirred for additional 15 hours. Water (10 ml) and Et2O (10 ml) were added and the pH of the aqueous layer was set to pH >9 by adding some saturated NaHCO3 (aq.). The organic layer was separated and the aqueous layer was washed with Et2O (3×15 ml). The pH of the aqueous layer was subsequently set to pH <2 with some 10% HCl (aq.) and was extracted with Et2O (3×20 ml). The combined organic extracts were dried over anhydrous Na2SO4. The solvents were removed in vacuo yielding 473 mg of a solid with a purity of circa 56% (determined by 1H NMR), 18% yield of adipic acid. N.B. NMR showed other compounds as well, including 2,6-dichlorobenzoic acid.

Provenance & Evidence