Hydrochloric Acid → 2-Hydroxy-5-phenoxybenzaldehyde

Participants

Reaction Conditions

Reaction Steps

Ethyl magnesium bromide (67.5 mL of an approximately 3.0 M solution in diethyl ether, 202.5 mmol) was added to toluene (50 mL). A solution of 4-phenoxyphenol (25.00 g, 134.26 mmol) in diethyl ether (35 mL) was added resulting in the evolution of gas. The reaction was heated to 80° C. causing distillation of the diethyl ether. Toluene (300 mL), HMPA (23.4 mL, 24.059 g, 134.26 mmol), and paraformaldehyde (10.07 g, 335.65 mmol) were added and the reaction was heated to 85° C. for 4 hours. The reaction was cooled to room temperature and was acidified with 2N HCl. The resulting layers were separated and the organic phase collected. The organic phase was washed with brine. The combined aqueous phases were extracted with methylene chloride. The organic phases were combined, dried over MgSO4, filtered and concentrated in vacuo yielding a yellow oil. The oil was purified by silica flash chromatography (hexanes-ethyl acetate, 95:5). Concentration in vacuo of the desired fractions provided the salicylaldehyde as a pale yellow powder (12.0 g, 42%) of suitable purity to use in subsequent steps.

Provenance & Evidence