Phenol → 2H-Pyran-4-carboxylic acid, tetrahydro-, methyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 94 grams (1.0 mol) of phenol, 5.31 g (0.0500 mol) of 3-mercaptopropionic acid, 10 g of LEWATIT BE ion exchange resin and 1.0 g of 2,6-dimethylnaphthalene (internal standard for liquid chromatography analysis) was heated to about 65° C. in a round bottom flack equipped with a distillation setup, an internal thermometer and a mechanical stirrer. The solution was continuously sparged with nitrogen (using a dip tube) to remove the water. To this mixture was added 11.35 g (0.8336 mol) of 4-hydroxyacetophenone. The mixture was stirred at about 65° C with the nitrogen sparge for about 8 hrs. The THPE was isolated by precipitation with methylene chloride (4 mL/1 g of reaction mixture) and the yield is given in Table III.

Provenance & Evidence