Methanol → HCID 22012605, compound

Participants

Reaction Steps

To a solution of Example 1A (11.95 g, 3.9 mmol) in dioxane was added water (40 mL) until the solution just clouded and then dioxane was added until the solution became clear again(˜5 mL). Oxalic acid (9.83 g, 78.0 mmol) was added in a single portion to give a dark orange solution which became a thick slurry. To the slurry was added in sequence: water (110 mL), dioxane (60 mL), and methanol (20 mL). This gave a mostly homogeneous solution with some small crystals which eventually dissolved as the reaction mixture was stirred for 1 hour. The volume of the reaction was reduced to ⅓ of the original volume by concentration under vacuum. The resulting solution was extracted (3×, ethyl acetate). The organic extracts were combined and washed (2×, 10% aqueous HCl; 2×, saturated aqueous NaHCO3; 2×, brine), dried (Na2SO4), filtered and concentrated under vacuum to give a thick orange-yellow oil which was dried under vacuum at 45° C. to a constant weight providing the title compound (7.03 g, 79%) as a orange-yellow solid. This material was pure by 1H NMR. A small portion was recrystallized from ether/hexanes.

Provenance & Evidence