Hexamethylenetetramine → 4-tert-Butyl-2-hydroxybenzaldehyde

Participants

Reaction Conditions

Reaction Steps

A five liter three-neck round bottom flask equipped with overhead mechanical stirrer and condenser was charged with trifluoroacetic acid (2.4 L). A mixture of 3-tert-butylphenol (412 g, 2.8 mole) and HMTA (424 g, 3.0 mole) was added portion-wise causing an exotherm. With cooling, the temperature was maintained under 80° C. The reaction was heated at 80° C. for one hour, then cooled, and water (2 L) added. After 0.5 hour additional water (4 L) was added and the mixture was extracted with ethyl acetate (6 L). The organic extract was washed with water and brine. The resulting organic phase was divided into 2 L volumes and each diluted with water (1 L), and solid NaHCO3 added until the mixture was neutralized. The organic phases were isolated and combined, dried over MgSO4, filtered and concentrated in vacuo yielding an oil. This oil was distilled at 95° C. (0.8 mm) yielding the desired salicylaldehyde as an oil (272.9 g, 56%) which was of sufficient purity to be used without further purification.

Provenance & Evidence