Hydrochloric Acid → 2-Chloro-4-hydroxybenzaldehyde

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Reaction Steps

3-Chlorophenol (CAS 108-43-0) (49.2 g, 0.380 mol), calcium hydroxide (122.0 g), and sodium carbonate (139.4 g) were suspended in water (872 mL). Chloroform (90.6 g, 0.760 mol) was added for 80 min, and the mixture was refluxed under vigorous stirring for 3 h. The reaction mixture was cooled on ice bath. Concentrated HCl (385 mL) and chloroform (300 mL) were added. The aqueous layer was discarded. The organic one was dried with anhydrous Na2SO4 (50 g) and evaporated in vacuo. The residue was purified by chromatography (silica gel 63-100 μm, 600 g, CCl4→CHCl3→CHCl3/EtOAc 93:7). Fractions containing the product were combined, evaporated, and coevaporated with dioxane to give the title compound (9.77 g, 0.062 mol, 16%) as a white powder. 1H NMR data (DMSO-d6): 11.06 (s, 1H, COH); 10.14 (s, 1H, OH); 7.75 (d, 1H, J=8.5 Hz, Ar—H); 6.92 (d, 1H, J=2 Hz, Ar—H); 6.85 (d.d., 1H, J1=8.5 Hz, J2=2 Hz, Ar—H).

Provenance & Evidence