At a time when even colossal business deals are often carried out via speakerphones and videoconferencing, Merck & Co.’s $14.2 billion sale of such brand lines as Claritin and Coppertone to Germany’s Bayer AG played out like a throwback to the “Mad Men” era.

“When we were down to the wire, we had 40 people fly in from Germany from Bayer, and Merck brought in 35 from New Jersey and other parts of the Merck empire for face-to-face meetings for a week,” says former Fried, Frank, Harris, Shriver & Jacobson M&A co-head David Shine, who represented Merck. “I’ve done multibillion-dollar deals where no one met face to face.” (Shine lateraled to Paul Hastings in March.)