The company denied the allegations. In a statement at the time, Mr. Solomon said, “We remain dedicated to ensuring that we operate in full compliance with all laws and regulations.”
In 2011, Forest Labs won a proxy fight against the shareholder activist Carl C. Icahn, who had argued that the company had lost billions of dollars of shareholder value over the previous decade. Mr. Icahn continued to pursue Forest Labs with a second proxy fight in 2012, which ended with one of his nominees elected to the company’s board.
In a letter to Mr. Icahn during that fight, Mr. Solomon wrote: “Your discourse thus far has shown a striking lack of strategic ideas. Instead, it has been replete with wild and baseless accusations, innuendo and distortion of facts.”
Still, at some point, Mr. Solomon reached out to Mr. Icahn, and they had a series of dinners.
“We got friendly,” Mr. Icahn said in a phone interview. “I thought he was a nice gentleman, a courtly guy.” He added: “I didn’t agree with the way he ran the business necessarily, but he was a nice guy who was thrilled with the outcome. He made a lot of money.”
In 2013, Mr. Solomon announced his retirement as chief executive and was replaced by Brent Saunders, an executive friendly with Mr. Icahn. Then, in early 2014, Actavis (now Allergan) paid $25 billion to acquire Forest Labs. Mr. Solomon, still the chairman, left after the acquisition and formed a family investment firm with his younger son, David, who had been a Forest Labs executive and who also survives him.
In addition to his sons, Mr. Solomon is survived by his wife, Sarah Billinghurst Solomon, a former assistant general manager of artistic affairs at the Metropolitan Opera, and five grandchildren. His first wife, Carolyn (Bower) Solomon, died in 1991.
Mr. Solomon had extensive philanthropic interests, especially opera. As a teenager he paid for piano lessons at the Manhattan School of Music by selling librettos to patrons of the old Metropolitan Opera on 39th Street and Broadway. He later became chairman of the Met’s finance committee, chairman of New York City Ballet and a board member of Lincoln Center.
His desire to work into his 80s was, he said, inspired by the example of Giuseppe Verdi.
“Growing up, he’d talk about Verdi writing ‘Falstaff’ in his 80s,” Andrew Solomon said. “‘Imagine that,’ he’d say, ‘in his 80s, he wrote some of the greatest music ever written.’ That was the path he hoped to follow.”