Telomerization of isobutylene with carbon tetrachloride in the presence of copper salts- aliphatic amines as the initiator system was investigated, and the 1 : 1 adduct (1, 1, 1, 3-tetrachloro-3-methylbutane) was obtained in yields over 90 mol %, based on the isobutylene. Then the hydrolyses of 1 : 1 adduct with sulfuric acid were carried out under various reaction conditions.
From the results of these investigations, it was confirmed that β β-dimethylacrylic acid is prepared in a two-stage process from isobutylene in overall yield of 7080 mol %, based on isobutylene.