US3833651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of dl-methionine
Assignee: DEUTSCHE GOLD und SILBER SCHEIDEANSTALT DT
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Filing: 1971-08-05
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Granted: 1974-09-03
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Expires: 1991-08-05
Abstract
Abstract IMPROVED PROCESS FOR THE PREPARATION OF DL-METHIONINE WHEREIN THE ADDITION REACTION METHYL MERCAPTAN AND HYDROCYANIC AICD TO ACROLEIN AND THE HYDANTOIN RING FORMING REACTION ARE SIMULTANEOUSLY EFFECTED IN ONE-STAGE TO GIVE A HYDANTOIN TYPE INTERMEDIATE, WHICH IS THEN HYDROLYZED. THE PROCESS CAN BE SIMPLY AND EASILY CONDUCTED TO OBTAIN HIGH PURITY DL-METHIONINE IN HIGH YIELD AT LOW COST.
Inventors
- 👤 S Ouchi
- 👤 C Shibuya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:10
CPC Classifications
C; C07; C07C; C07C323/00; C07C323/50; C07C323/51; C07C323/57; C07C323/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |