The record-breaking $43 billion acquisition of Swiss agrochemical giant Syngenta AG by Chinese state-owned China National Chemical Corp. was a case study of corporate persistence and diplomacy.

In order to pull off the landmark all-cash deal—the largest ever outbound acquisition by a Chinese company—ChemChina had to win over a reluctant seller, which had just fought off a series of hostile bids from United States rival Monsanto Co., and agree to a series of unprecedented concessions over Syngenta's future governance.

Lawyers also had to contend with an almost impossibly tight timescale, an antitrust process that would involve regulators in 20 jurisdictions, and the small matter of raising financing equivalent to the gross domestic product of Slovenia.