PURPOSE: To obtain industrially advantageously the titled high-purity compound by an easy liquid separation operation with suppressing coloring of reaction solution, by adding previously water to 1,4-butylene glycol, etc., before a hydrogen chloride gas is introduced and introducing the hydrogen chloride gas to 1,4-butylene glycol, etc.

CONSTITUTION: Water or an aqueous solution of hydrochloric acid is previously added to 1,4-butylene glycol or tetrahydrofuran and a hydrogen chloride gas is introduced to 1,4-butylene glycol or tetrahydrofuran to carry out a reaction. After the reaction is over, the reaction mixture is separated into an organic layer and a water layer, to give high-purity 1,4-dichlorobutane. An amount of water added is preferably ≥5wt% based on the raw material, 1,4-butylene glycol, etc., and when the aqueous solution of hydrochloric acid is used, its concentration is 0wt% W concentration of saturated aqueous solution of hydrochloric acid.

EFFECT: A reaction mixture is easily separated into an organic layer and a water layer.

USE: An intermediate for synthesizing drugs and agricultural chemicals.