L-Methionine → 3,6-bis[2-(methylthio)ethyl]piperazine-2,5-dione

A suspension of 13.4 g (0.09 mol) of methionine, 17.2 g (0.09 mol, purity: 91%) of methioninehydantoin (IId) and 150 g of water were introduced into a 200 ml Roth steel autoclave with magnetic stirring and stirred at 160° C. for 6 hours, during which the pressure increased to 15 bar. From time to time, the autoclave was decompressed until the pressure settled at a constant 10 bar. The autoclave was then cooled in an ice bath, and the resulting suspension was filtered and the solid was washed with 75 ml of water. Finally, the solid was dried in a vacuum drying oven at 50° C. overnight. Bis[2-(methylthio)ethyl]-2,5-piperazinedione (III) was isolated as yellowish white crystals.

1. stirringstirred at 160° C. for 6 hours, during which the pressure
2. temperatureincreased to 15 bar
3. temperatureThe autoclave was then cooled in an ice bath
4. filtrationthe resulting suspension was filtered
5. washthe solid was washed with 75 ml of water
6. customFinally, the solid was dried in a vacuum
7. customdrying oven at 50° C. overnight

ORD record

ord-6ccbbcd80090488ea5d8a7c08c1cd5be

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09095161B2