Thionyl Chloride → (2E)-3-(3-Fluorophenyl)-2-propenoyl chloride

Participants

Reaction Steps

A mixture of trans 3-fluorocinnamic acid (32.3 g), thionyl chloride (48 g) and dry benzene (300 ml) was heated at reflux for 2 hours. Solvent and excess thionyl chloride were removed by distillation under reduced pressure leaving trans 3-fluorocinnamoyl chloride (34 g) as an oil. A solution of trans 3-fluorocinnamoy chloride (3.3 g) in dry toluene (100 ml) was added with stirring to a solution of cyclopropylamine (2.5 g) in dry ether (100 ml) at ambient temperature. The reaction mixture was heated at 30°-34° C. for 2 hours, and the solvent and excess amine were removed under reduced pressure. The residue was triturated with water, filtered and recrystallized from ethanol:water (1:10) to give trans 3-fluoro-N-cyclopropylcinnamamide (3.3 g), m. p. 90°-91° C.

Provenance & Evidence