Ethanol → Ethyl 5-formyl-2-hydroxybenzoate

Reaktionsgleichung

[CH:1]([C:3]1[CH:11]=[C:7]([C:8]([OH:10])=[O:9])[C:6]([OH:12])=[CH:5][CH:4]=1)=[O:2].S(=O)(=O)(O)O.[CH2:18](O)[CH3:19]>>[CH:1]([C:3]1[CH:4]=[CH:5][C:6]([OH:12])=[C:7]([CH:11]=1)[C:8]([O:10][CH2:18][CH3:19])=[O:9])=[O:2]

Komponenten

Edukt 3

HCID 702Ethanol

HCID 1118Sulfuric Acid

HCID 692265-Formylsalicylic acid

Produkt 1

HCID 18930679Ethyl 5-formyl-2-hydroxybenzoate

Versuchsvorschrift

5-Formylsalicylic acid (3.0 g, 17 mmol), conc. sulfuric acid (1 mL) and absolute ethanol (100 mL) were heated at reflux for 3.5 days with stirring under N2. The reaction was cooled, then carefully quenched by adding saturated sodium bicarbonate (40 mL). Solvent was removed in vacuo, and the resulting mixture was acidified with 1 M HCl (50 mL), then extracted with EtOAc. The organic phase was extracted with water, then brine, and dried (MgSO4). Removal of solvent and chromatography on silica gel, eluting with 0% to 25% EtOAc in hexanes gave a colorless crystalline solid (2.3 g), mp 67°-69° C., after solvent removal. 1H-NMR(300 MHz, CDCl3): 11.49 (s, 1H), 9.90 (s, 1H), 8.40 (d, 1H, J=2 Hz), 8.00 (dd, 1H, J=8,2 Hz), 7.11 (d, 1H, J=8 Hz), 4.48 (q, 2H, J=7 Hz), 1.46 (t, 3H, J=7 Hz). IR (KBr): cm-1 3186, 1684.