Raymond Sackler, a pioneer in psychopharmacology, a medicinal products entrepreneur and a leading philanthropist whose family made a fortune from the opioid painkiller OxyContin, died on Monday in Greenwich, Conn. He was 97. His death was confirmed by his wife, Beverly. Dr. Sackler was the last survivor among three brothers — all psychiatrist sons of Brooklyn grocers — whose scientific and marketing skills transformed a tiny Greenwich Village company founded in the 19th century into a global pharmaceutical giant known as Purdue Pharma, now headquartered in Stamford, Conn. Last year, the Sacklers were ranked 19th among “America’s richest families” by Forbes magazine, with assets estimated at $18 billion. Raymond was the middle brother and was regarded as the most retiring. Arthur, the eldest, died in 1987, Mortimer in 2010. The brothers founded the Creedmoor Institute of Psychobiological Studies at the state hospital in Queens Village, N.Y. (Raymond and Mortimer, who were studying skin burns for the Atomic Energy Commission there, were dismissed in 1953 when they refused to sign an Army loyalty oath requiring them to report participants who engaged in conversations deemed subversive.) It was Arthur Sackler, a trailblazer in medical advertising, who financed the purchase of a small Greenwich Village drug manufacturer, the Purdue Frederick Company, in 1952. Raymond Raphael Sackler was born on Feb. 16, 1920, in Brooklyn to Isaac Sackler and the former Sophie Ziesel, Jewish immigrants from Eastern Europe who ran a grocery store. After graduating from Erasmus Hall High School in Brooklyn, he earned a bachelor of science degree from New York University in 1938. At a time when medical schools in New York imposed quotas on the number of Jewish students they would admit, Raymond Sackler pursued his medical degree at Anderson College of Medicine in Glasgow, where he also joined the British Home Guard and served as a plane spotter during World War II. He graduated from Middlesex University Medical School in Waltham, Mass. (It closed later in the 1940s.) In 1944, Dr. Sackler married the former Beverly Feldman, who survives him. Survivors also include their two sons, Richard and Jonathan.