Complex sentence: After receiving his Ph.D. in organic chemistry from Iowa State University in 1981, he spent a year as a Postdoctoral Fellow at the University of Rochester, then joined Parke-Davis of Warner-Lambert Company as a Medicinal Chemist in 1982.
Split into simpler sentences: After receiving his Ph.D. in organic chemistry from Iowa State University in 1981, he spent a year as a Postdoctoral Fellow at the University of Rochester. Roth joined Parke-Davis of Warner-Lambert Company as a Medicinal Chemist in 1982.