1-Hydroxy-2-naphthoic acid → 4-Methoxybenzyl 1-hydroxynaphthalene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

(This is a compound 15a of Scheme 1). A suspension of powdered sodium salt of 1-hydroxynaphthalene-2-carboxylic acid (1) (61.3 g, 0.29 mmol) in DMSO (205 mL) was treated with 4-methoxybenzyl chloride (98%, 46.7 g, 0.29 mmol) and then stirred at 70° C. for 1 h. After cooling, the mixture was poured into dilute aqueous KHCO3 (3.5 L) and the resulting precipitate was collected, washed with water and dried. The solid was extracted with boiling petroleum ether (bp 60-65° C., 1100 mL), treated with decolourising charcoal and the filtered solution was cooled for a prolonged period at 0° C. to provide crude 4-methoxybenzyl 1-hydroxynaphthalene-2-carboxylate (2) (59.4 g, 66%), suitable for further use. A sample was recrystallised from iPr2O/petroleum ether, mp 92-93° C. 1H NMR [(CD3)2SO] δ 11.91 (s, 1H, OH), 8.31 (d, J=8.2 Hz, 1H, H-3), 7.92 (d, J=8.1 Hz, 1H, H-4), 7.73 (d, J=8.8 Hz, 1H, ArH), 7.71 (brt, J=7.5 Hz, 1H, ArH), 7.61 (br t, J=1.6 Hz, 1H, ArH), 6.99 (d, J=8.6 Hz, 2H, H-3',5'), 5.40 (s, 2H, CH2), 3.34 (s, 3H, CH3). Anal. Calculated for C19H16O4): C, 74.0; H, 5.2. Found: C, 73.7; H, 5.2%.

Provenance & Evidence