3,5-Dimethoxybenzoic Acid → 3,5-Dimethoxybenzyl alcohol

Participants

Reaction Conditions

Reaction Steps

A stirred suspension of lithium aluminum hydride (13.1 g, 329 mmol, 2 equiv) in dry THF (400 mL) was cooled at 0° C. A solution of 3,5-dimethoxybenzoic acid (30.0 g, 164 mmol, 1 equiv) in dry THF (400 mL) was added over 45 min via addition funnel. Upon completion of the addition the reaction became a gray heterogeneous mixture, therefore and additional 300 mL of THF was added. The reaction mixture was allowed to warm to room temperature and stir for 5 h. The reaction mixture was quenched with a saturated aqueous solution of Na/K tartrate added. The resulting mixture was allowed to stir at room temperature for 1 h and the organic layer was separated. The remaining aqueous layer was extracted with EtOAc (×2). The combined organic layers were dried (MgSO4), filtered, and concentrated under reduced pressure to give 27.0 g (97% yield) of 5 product as a colorless oil: Rf 0.33 (EtOAc/hexanes, 1:2); IR (CDCl3) 3390, 2937, 1594, 1456, 1428, 1318, 1294, 1202, 1146, 1057, 829 cm−1; 1H NMR (600 MHz, CDCl3) δ 6.45 (d, 2 H, J=2.4 Hz), 6.32 (d, 1 H, J=2.4 Hz), 4.50 (d, 2 H, J=5.4 Hz), 3.71 (s, 6 H), 3.49 (t, 1 H, J=5.4 Hz); 13C NMR (150 MHz, CDCl3) δ 160.5, 143.3, 104.2, 99.2, 64.5, 55.0.

Provenance & Evidence