Methanol → HCID 59710724, compound

Participants

Reaction Steps

An aqueous solution of sodium hydroxide (5M, 100 mL) was added under cooling to a solution of 5 (0.5 mol) in methanol (1.5 L). The mixture was stirred for 3 days at room temperature. The solvents were removed under reduced pressure and the residue dissolved in hot acetone (2 L). A thick paste precipitated from the acetone solution overnight (room temperature). TLC reveals that the upper acetone solution mainly contained the starting diester and the mono-sodium salt of the acid and that the lower paste was a mixture of the mono- and disodium salt of the acid. Acetone was removed from both fractions and the chromatographic separation on a gradient flash silica gel column (0-3% methanol in CH2Cl2) of both fractions gave 40 g the desired product. Yield 63%. 1H NMR (500 MHz, CDCl3, 25° C.), δ: 3.913 (s, 3H, OCH3), 3.982 (s, 3H OCH3), 7.252 (t, J=7.75, 1H, ArH), 7.991 (d, J=7.5, 1H, ArH), 8.166 (d, J=7.5, 1H, ArH). 13C NMR (500 MHz, CDCl3, 25° C.), δ: 52.48, 64.09, 124.10, 125.67, 136.38, 136.49, 159.76, 165.46, 167.69.

Provenance & Evidence