PURPOSE: To obtain the titled compound useful for preparing medicines in a reduced reaction time economically on high yield, by reacting an inexpensive and easily handleable prenyl chloride with a specific phenolic derivative in the presence of I2, etc. as a catalyst.

CONSTITUTION: A phenolic derivative of formulaI{R1, R2 and R3 are H, OH, prenoxy or polyprenoxy of formula II[(n) is 0 or an integer 1W19], carboxyalkoxyl of formula III[R is H or alkyl; (m) is an integer 1W5], etc.; R4 is H, alkyl, formula IV (R5, R6 and R7 are the same as R1, R2 and R3) or formula V, provided that at least one of R1WR7 is OH}is reacted with prenyl chloride or polyprenyl chloride of formula VI in the presence of a base, e.g. K2CO3, and a catalyst of I2 or an inorganic iodide to give the aimed compound. NH4I and a compound of an element belonging to GroupsIWVIa and VIb in the periodic table, e.g. KI, are used as the inorganic iodide.

USE: An intermediate for chalcone derivatives, etc. which are antipeptic ulcer agent.