Hydrochloric Acid → HCID 57451841, compound

Participants

Reaction Steps

The mixture of 2-ethoxy-6-formylphenylboronic acid (80 g, 0.41 mol), NaOH (16.5 g, 0.41 mol) and CTAB (7.7 g, 20 mmol) in H2O (100 mL) and THF (500 mL) was stirred for 0.5 h at room temperature After dropwise addition of nitromethane (14 mL, 2.4 mol), the reaction mixture was stirred at room temperature for 3 h. Then the cyclization was afforded by adding the diluted HCl (2 N) to pH=2 and then extracted with EtOAc (3×300 mL). The combined organic layers were washed with brine (250 mL), dried over anhydrous Na2SO4 and concentrated to dryness in vacuo. The residue was purified by column chromatography on silica gel to give the target compound as white solid (92 g, yield 94%). 1H NMR (400 MHz, DMSO-d6 δ 9.06 (s, 1H), 7.46-7.43 (t, 1H), 7.07-7.05 (d, 1H), 6.89-6.87 (d, 1H), 5.71-5.69 (m, 1H), 5.31-5.27 (m, 1H), 4.57-4.51 (m, 1H), 4.12-4.07 (m, 2H), 1.34-1.30 (t, 3H).

Provenance & Evidence