produced by Upjohn. Upjohn developed a process for the large scale production of
cortisone. The oxygen atom group must be in position 11 for this steroid to function. There are, however, no known natural starting materials with an oxo-group in position 11. The only method for preparing cortisone prior to 1952 was a lengthy synthesis, starting from
cholic acid isolated from bile. In 1952, two Upjohn biochemists, Dury Peterson and Herb Murray, announced that they had invented a new method by fermenting the steroid
progesterone with a common mold of the genus
Rhizopus. Over the next several years, a group of chemists headed by John Hogg developed a process for preparing cortisone from the soybean sterol
stigmasterol. The microbiological oxygenation invented by Peterson and Murry is a key step in this process. Subsequently, Upjohn (together with
Pharmacia) biochemically converted cortisone into the more potent
steroid prednisone via bacterial fermentation. In
chemical research, the company is known for the development of the
Upjohn dihydroxylation by V. VanRheenen, R. C. Kelly, and D. Y. Cha in 1976. Upjohn's best known drugs before its acquisition by Pfizer were
Xanax,
Halcion,
Motrin,
Lincocin, and
Rogaine. In 1995, Upjohn merged with
Pharmacia AB to form
Pharmacia & Upjohn. The company was owned by
Pfizer from 2002 until 2020. In 2015, Pfizer resurrected the Upjohn brand name for a division which manufactures and licenses drugs with patents that have expired. Pfizer planned to divest itself of this business in 2020. In July 2019, Pfizer announced plans to merge Upjohn with
Mylan. The merger was expected to close in the first half of 2020, was delayed due to the
COVID-19 pandemic, and finally completed in November 2020. The resultant entity was named
Viatris. ==See also==