They were bought by Bayer, which isn't much better, but they pretty much did do that:
https://media.bayer.com/baynews/baynews.nsf/id/Bayer-launch-...
https://media.bayer.com/baynews/baynews.nsf/id/Bayer-launch-...
https://www.bayer.com/en/agriculture/agriculture-biologicals
In 1925 Bayer merged with five other German companies to form IG Farben
IG Farben the made Zyklon B, and as a result it got split up after the war, into it's original companies, one of them bayer.
So, yes, you are mostly correct.