3-Methylthiophen

VerwendenThiophene, 2-methyIthiopheney and 3-methylthiophene act as inhibitors for the polymerization of trichloroethylene in a solvent used for the degreasing of iron and aluminum, said polymerization being catalyzed by contact of the solvent with the metals. Bonz, in 1885, reported the formation of a dichloroethylthiophene from chlorination of 2-ethylthiophene in the cold. Is Opolski studied the chlorination of 2- and 3-methylthiophenes, 2-ethyl- and 2-butylthiophene and reported constants for the monochloro derivatives. Voerman has chlorinated 3-methylthiophene in the side chain with phosphorus trichloride in the sunlight, but concurrent ring chlorination predominates. 3-Methylthiophene gives a unique reaction with alkyl- or arylsodium in which the substitution takes place exclusively in the 5-position rather than in the expected 2-position.