The synthesis of 3-vinylthiophene was efficiently achieved in two steps. 3-
(2-bromoethyl)thiophene prepared from 3-(2-ethanol)thiophene was converted
to the title compound (70% overall yield) using tetraglyme as a solvent and
1,8-diazabicyclo [5.4.0] undec-7-ene as a base.