Methanol → Methyl 4-Formylbenzoate

Participants

Reaction Steps

A 500-mL, three-necked, round bottom flask was eqipped with a teflon-coated stirring bar, soxlet extractor and condensor with drying tube at the top. The flask was charged with 10.0 g (66.6 mmol) of 4-formylbenzoic acid, about 320 mL of absolute CH3OH and 0.1 mL of concentrated H2SO4. The soxlet extractor was filled with 3 Å molecular sieve. After the solution was boiled for 48 hours, it was allowed to cool to room temperature and then was concentrated to a volume of about 50 mL, diluted with an equal amount of water, and extracted (ether 4×70 mL). The combined organic layers were washed with saturated NaHCO3 solution (5×50 mL), 0.1 NHCl (10×40 mL), H2O (2×50 mL), and saturated NaCl solution (2×50 mL). The resulting organic solution was finally dried (MgSO4, 2 h) and filtered and concentrated in vacuo. The white solid obtained was recrystallized (hexane) to give 6.3 grams (57.6%) of ester 33 mp 59.5°-60° C. [literature reports 59°-60° C.; see J. M. Landesberg, M. A. Slam, and M. Mandel J. Org. Chem., 46, 5025 (1981)]; IR (KBr) 1680-1740 cm-1 (C=O); 1H NMR (DCCl3) δ4.00 (s, 3H, OCH3), 7.80=8.32 (m, 4H, Ar-H), 10.10 (s, 1H, CHO); 13C NMR (DCCl3)ppm 52.6 [OCH3 ], Ar-C [129.6, 130.4, 135.2, 139.2], 166.0 [CO2CH3 ], 191.7 [CHO]; mass spectral data for C9H8O3 : m/e (M+): 164.0473. Found: 164.0472. ##STR19##

Provenance & Evidence