Acetic Acid → 5-Chloro-2-ethyl-3-[ethyl(oxan-4-yl)amino]benzoic acid

Participants

Reaction Steps

To a solution of methyl 5-chloro-2-ethyl-3-[(oxan-4-yl)amino]benzoate (350 mg, 1.18 mmol) in DCE (10 ml) at room temperature and under nitrogen was added acetaldehyde (0.66 ml, 11.75 mmol) followed by acetic acid (0.4 ml, 7.05 mmol). This solution was stirred for 5 minutes before the addition of sodium triacetoxyborohydride (2.49 g, 11.75 mmol) at room temperature. After stirring for 23 h further acetaldehyde (0.66 ml, 11.75 mmol) was added followed sodium triacetoxyborohydride (2.49 g, 11.75 mmol). After stirring for a further 3 hours deionized water (15 ml) was added and the mixture was neutralized with solid NaHCO3. The phases were separated and the aqueous layer was extracted with EtOAc (2×15 ml). The combined organic extracts were dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified by FCC (10 g silica, Isolute cartridge, gradient of eluents; 99:1 Heptane:EtOAc to 85:15 Heptane:EtOAc) to afford the title compound (317 mg) as a 2:1 mixture of methyl and ethyl esters that were used in the next stage.

Provenance & Evidence