US 12,187,669 B2
Method for producing methionine
Daniel Sudhoff, Bergkamen (DE); Judith Hierold, Hanau (DE); Philipp Roth, Hanau (DE); Imad Moussallem, Hanau (DE); Ulf Bindernagel, Cologne (DE); and Christian Renner, Gründau (DE)
Assigned to Evonik Operations GmbH, Essen (DE)
Appl. No. 17/413,540
Filed by EVONIK OPERATIONS GMBH, Essen (DE)
PCT Filed Dec. 13, 2019, PCT No. PCT/EP2019/085005
§ 371(c)(1), (2) Date Jun. 12, 2021,
PCT Pub. No. WO2020/120720, PCT Pub. Date Jun. 18, 2020.
Claims priority of application No. 18212499 (EP), filed on Dec. 14, 2018.
Prior Publication US 2022/0048855 A1, Feb. 17, 2022
Int. Cl. C07C 319/20 (2006.01); C07D 233/76 (2006.01)
CPC C07C 319/20 (2013.01) [C07D 233/76 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for producing 2-hydroxy-4-(methylthio) butyronitrile (MMP-CN), comprising:
a) preparing a crude HCN process gas mixture by Andrussow HCN synthesis from methane, ammonia and oxygen;
b) preparing an HCN process gas mixture by adjusting the amount of ammonia in the crude HCN process gas mixture to between 20% (v/v) and 60% (v/v) of the amount present before adjustment; and
c) contacting the HCN process gas mixture with 3-methyl-mercaptopropionaldehyde (MMP).