PURPOSE: To obtain the titled compound useful for preparing organic semiconductors, etc. in high yield with an easy synthesis of raw material, by reacting sodium acetylide with thiophene bromide in the presence of a crown ether in a hydrocarbon solvent.

CONSTITUTION: In reacting sodium acetylide with thiophene bromide in a hydrocarbon solvent (e.g., toluene, xylene, etc.), the reaction is carried out in the presence of a crown ether as a reaction auxiliary, to give a thiophene derivative containing an acetylene residue. For example, 1,4,7,10-tetraoxacyclodecane (usually called 12-crown-4), etc. may be cited as the crown ether. The amount of the crown ether added is 0.1W10mol% based on thiophene bromide. The derivative by this method can be polymerized easily, its polymer is free from problems such as insolubility in solvent, being easily oxidized, etc. and preferably applied to an organic sensor, solar battery, etc.