Sodium Carbonate → Sodium Bicarbonate

Participants

Reaction Conditions

Reaction Steps

The residue of Step 2 was dissolved in isopropyl acetate (10 vol), water (0.5 vol) was added, and the mixture was cooled to 0° C. A solution of cerium (IV) ammonium nitrate (2.74 wt) in water (3 vol) was prepared at room temperature and buffered by addition of saturated aqueous sodium carbonate solution (17.4% w/w; 0.75 vol). The buffered cerium (IV) ammonium nitrate solution was added over 30 min to the prepared mixture of alpha-tocotrienol from step 2 in isopropylacetate and water while maintaining the temperature at 0° C. The mixture was stirred at 0° C. and monitored for conversion of starting material components to product components. The organic layer was separated and treated for 2 h with a slurry of solid sodium hydrogen carbonate (2 wt) and solid sodium sulfate (2 wt) in isopropylacetate (5 vol). The suspension was filtered, the solids washed with isopropylacetate (1.5 vol), and the combined filtrates treated with sodium hydrogen carbonate (2×0.05 wt). The suspension was concentrated to a maximum extent while maintaining an agitable mixture by distillation at up to 45° C. under vacuum. The residue was cooled to 30° C. and diluted with n-heptane (10 vol). A chromatography column of silica gel (5 wt) and sodium hydrogen carbonate (0.05 wt) was prepared from a slurry in n-heptane. The mixture was eluted on the chromatography column and further eluted with mixtures of n-heptane/isopropylacetate in relative volume-ratios of 100:5 and then 100:10. Fractions were collected, treated with solid sodium hydrogen carbonate (ca. 0.1 to 1 g/L eluent), and analyzed for product content and purity. Acceptable fractions were combined, treated with additional solid sodium hydrogen carbonate (0.05 wt), and concentrated to a maximum extent while maintaining an agitable mixture by distillation of solvent at up to 45° C. under vacuum. Isopropylacetate (1 to 3 vol) was added and the mixture passed through a 0.45 to 1 um filter. The filtrate was evaporated to dryness by distillation of solvent at up to 40° C. under vacuum to give the product, alpha-tocotrienol quinone. 1H-NMR (400 MHz, C6D6) 5.37-5.28 (t br m, J=7 Hz, 2H), 5.28-5.20 (t br m, J=6 Hz, 1H), 2.53-2.46 (m, 2H), 2.25-2.15 (m, 6H), 2.15-2.07 (m, 4H) 1.91 (s, 3H), 1.73-1.71 (br d, J=1 Hz, 3H), 1.71-1.70 (br d, J=1 Hz, 3H, 1.68 (s, 6H), 1.62 (s, 3H), 1.57 (s, 3H), 1.54-1.47 (m, 2H), 1.47-1.40 (ddd, J=8.6.1 Hz, 2H), 1.10 (s, 3H), 1.00 (s, 1H).

Provenance & Evidence