Water → HCID 59637583, compound

Participants

Reaction Conditions

Reaction Steps

LTMP (7.5 mmol) is added at 0° C. to a solution of 4,6,7-trimethoxy-8-methyl-2-naphthoic acid (0.414 g, 1.5 mmol) in anhydrous THF (30 mL). The mixture is stirred for 2 h at 0° C. then trapped with MeI (0.943 mL, 15 mmol). After 2 h at 0° C., the reaction mixture is heated to ambient temperature and then hydrolysed with 30 mL of water. The aqueous phase is washed with ethyl ether (2×20 mL), acidified with 2M HCl (pH 1-2), then extracted with ethyl ether (3×30 mL). The combined organic phases are dried over MgSO4, filtered, then concentrated under reduced pressure. The residue is recrystallized (cyclohexane/ethyl acetate) to give 8-ethyl-4,6,7-trimethoxy-2-naphthoic acid (3) (0.392 g, 90%). 1H NMR (200 MHz, acetone-d6): 8.22 (s, 1H), 7.44 (s, 1H), 7.29 (s, 1H), 3.96 (s, 3H, OCH3), 3.89 (s, 3H, OCH3), 3.78 (s, 3H, OCH3), 3.02 (q, 2H, CH2), 1.16 (t, 3H, CH3). 13C NMR (100 MHz, DMSO-d6): 167.8, 154.2, 153.2, 146.9, 132.9, 127.0, 126.5, 125.0, 118.5, 102.6, 99.6, 60.6, 55.6, 55.4, 18.6, 15.4. IR (cm−1): 2940, 2826, 2637, 1682, 1464. SMHR, [M+H]+ calculated for C16H19O5: 291.1232. Found: 291.1230.

Provenance & Evidence