4-Hydroxybenzoic Acid → 4-hydroxybenzoyl Chloride

Participants

Reaction Steps

4-Hydroxybenzoic acid (11.04 g.) was heated under reflux with thionyl chloride (80 ml.) containing dimethylformamide (0.1 ml.) for 2 hours. The solution obtained was evaporated. The residue was dissolved in toluene and the subsequent solution was evaporated. The residue obtained (which contained 4-hydroxybenzoyl chloride) was dissolved in methylene chloride (80 ml.). The solution obtained was treated dropwise with 1,2,3,6-tetrahydropyridine to pH7 with stirring and ice-cooling. The mixture was further stirred at 25° C. after the addition was complete for 2 hours and then evaporated. The residue was stirred with water and the solid was collected by filtration and then washed with water and acetone. After recrystallisation from a mixture of ethanol and ethyl acetate, there was obtained 1-(4-hydroxybenzoyl)-1,2,3,6-tetrahydropyridine (11.3 g.), m.p. 202°-206° C.

Provenance & Evidence