Hydrochloric Acid → 5-Hydroxy-2-(2-methoxyethoxy)isonicotinaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-methoxy-5-(methoxymethoxy)isonicotinaldehyde (1.27 g, 5.29 mol) in THF (5 mL) was added HCl (3 N, 4 mL). The reaction was stirred at 50° C. for 1 h, cooled to RT, and diluted with water (5 mL). The mixture was neutralized to pH 7-8 with solid K2CO3 and the aqueous layer was extracted with EtOAc (100 mL) twice. The combined organic layers were dried over Na2SO4, concentrated, and purified on silica gel using a mixture of EtOAc and hexanes to give 5-hydroxy-2-(2-methoxyethoxy)isonicotinaldehyde (630 mg, 60%) and 5-hydroxy-2-(2-methoxyethoxy)nicotinaldehyde (120 mg, 11%). Data for 5-hydroxy-2-(2-methoxyethoxy)isonicotinaldehyde: 1H NMR (400 MHz, CDCl3) δ 9.98 (s, 1H), 9.50 (s, 1H), 8.07 (s, 1H), 7.02 (s, 1H), 4.51-4.39 (m, 2H), 3.81-3.72 (m, 2H), 3.47 (s, 3H). LRMS (M+H+) m/z 198.1. Data for and 5-hydroxy-2-(2-methoxyethoxy)nicotinaldehyde: NMR (400 MHz, CDCl3) δ 10.3 (s, 1H), 7.99 (d, J=3.2 Hz, 1H), 7.58 (d, J=3.2 Hz, 1H), 7.18-7.07 (br, 1H), 4.54 (dd, J=5.4, 3.7 Hz, 2H), 3.84 (dd, J=5.4, 3.7 Hz, 2H), 3.49 (s, 3H); MS (ESI) m/z 198.1 [M+H]+.

Provenance & Evidence