3,4-dihydro-2H-pyran → HCID 19086554, compound

Participants

Reaction Conditions

Reaction Steps

260.2 g (2.0 mol) of 2,4-difluorophenol and 252.4 g (3.0 mol) of 3,4-dihydro-2H-pyran are introduced into a 750 ml sulfation flask and cooled to 0° C. One drop of polyphosphoric acid is carefully added to the solution, and the mixture is stirred for a further 16 hours at 0° to 5° C. (check using GC and TLC). The mixture is then rendered alkaline using a little powdered sodium hydroxide. The product is distilled at 119°-120° C. in vacuo (22 mbar). 377 g (88% of theory) of a clear, colourless liquid are obtained.

Provenance & Evidence