Preparation
Preparation by reaction of propionitrile with phlo-roglucinol (Hoesch reaction);
Preparation by reaction of propionic anhydride with phloroglucinol
in the presence of concentrated sulfuric acid (one drop) at 130° for 5 min ? (65%)
in the presence of Amberlite IR-120 (cation exchange resin sulfonic acid ? type) at 160° for 2–3 h (42%). N.B.: Zeokarb 225 was found to be as effective
in the presence of boron trifluoride etherate at 10° (62–65%)
Preparation by reaction of propionyl chloride with phloroglucinol
in the presence of aluminium chloride in nitrobenzene/carbon disulfide ? solution (76%), in nitrobenzene at 60° (55%) or without solvent at 50° (70%)
in the presence of boron trifluoride etherate at 10° (compound ? 3) (62–65%).
