Imidazole → L-Methionine

A mixture of 1.74 g. of 5-(β-methylthioethyl)hydantoin, 68 mg. of imidazole and 20 ml. of water was heated to 160° C. in a 50 ml. autoclave and then allowed to react for 3 hours at 160° C., while being stirred. After the reaction was over, the autoclave was rapidly cooled to room temperature and the residual pressure was released. The autoclave was given a good wash with water to take off the reaction mixture, and then the reaction mixture was subjected to evaporation to dryness by means of a rotary evaporator. The resulting solid was shaken sufficiently with 100 ml. of methyl acetate. The methyl acetate insoluble matter was separated from the methylacetate solution. A portion of of the insoluble matter was recrystallized from water and then subjected to an infrared absorption spectrum and melting point measurements (m.p. 267° C., decomposed). Thus, it was found to be methionine. On the other hand, the methyl acetate soluble matter was found to be unreacted 5-(β-methylthioethyl)hydantoin and a negligible amount of by-products. According to a copper chelatemetric colorimetry of the insoluble matter (the colorimetry was conducted according to the method described in the specification of Japanese Laid-Open Patent Application No. 116008/1974), it was found that 0.75 g. of methionine (yield 50%) was attained.

1. additionA mixture of 1.74 g
2. customto react for 3 hours at 160° C.
3. washa good wash with water
4. customthe reaction mixture was subjected to evaporation to dryness by means of a rotary evaporator
5. stirringThe resulting solid was shaken sufficiently with 100 ml
6. customThe methyl acetate insoluble matter was separated from the methylacetate solution
7. customA portion of of the insoluble matter was recrystallized from water
8. customsubjected to an infrared absorption spectrum

ORD record

ord-730d3523be7a4721afd321df3cedacf0

Source dataset

uspto-grants-1978_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04082767