Preparation of dioctadienyl phthalate used as plasticizer in polyvinyl chloride composition

Preparation of dioctadienyl phthalates used as a plasticizer in polyvinyl chloride (PVC) compositions from 1,3-butadiene and phthalic acid comprises using a palladium catalyst stabilized with an orthophosphane ligand. Preparation of dioctadienyl phthalate comprises reacting 1,3-butadiene with phthalic acid in the presence of a palladium catalyst stabilized with an orthophosphane ligand of formula (R)n-P-(OR)m(I) and isolating the dioctadienyl phthalate. R = 4-20C alkyl or aryl; n and m = 0-3; and n + m = 3. Independent claims are included for the obtained dioctadienyl phthalate and resin compositions and paints containing the dioctadienyl phthalate.