PURPOSE: A 3-propenylsalicylic acid is converted into a halohydrin, dehydrogenated, reduced and deprotected in its 2-hydroxyl to give the titled compound as an intermediate of drugs inexpensively in high yield.

CONSTITUTION: A 3-propenylsalicylic acid with protected 2-hydroxyl of formulaI (R1 is hydrocarbon radical; R2 is protecting group; X is halogen) such as 2- hydroxy-3-propenylbenzoic acid or its ester is converted into its halohydrin with a halogenating agent such as Br2 to give 3-(α-hydroxy-β-halopropyl) derivative of formula III. The product is reduced with a reducing agent to prepare a compound of formula IV in which the halogen atom is replaced with a hydrogen atom, then the protecting group is removed, or both of reactions are effected simultaneously to give the objective compound of formula V.

USE: A starting material of 3-methylflavon-8-carboxylic acid used as an intermediate of drugs.