US2820827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of separating l- and d-aminomethyl-(3, 4-dihydroxyphenyl)-carbinol
Assignee: Hoechst AG
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Filing: 1954-10-26
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Granted: 1958-01-21
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Expires: 1974-10-26
Abstract
No abstract record available.
Inventors
- 👤 Ruschig Heinrich
- 👤 Stein Leonhard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:58
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/367; C07B; C07B57/00; C07C213/00; C07C213/10; C07C37/00; C07C37/68; C07C37/70; C07C37/84; C07B2200/00; C07B2200/07
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
THE PROCESS FOR SEPARATING L- AND D-AMINOMETHYL(3,4-DIHYDROXYPHENYL)-CARBINOL FROM AN EQUIMOLECULAR MIXTURE OF SAID BASES, WHICH COMPRISES HEATING SAID MIXTURE OF BASES ON THE STEAM BATH WITH AN ACID SELECTED FROM THE GROUP CONSISTING OF L-MANDELIC ACID AND D-MANDELIC ACID IN AN AHYDROUS LOWER ALKYL ALCOHOL TO THEREBY FORM SALTS OF SAID BASES WITH SAID ACID WHICH SALTS DISSOLVE IN SAID ALCOHOL, AND THEREAFTER COOLING SAID SOLUTION WHEREBY THE ACID SALT OF ONE OF SAID BASES PRECIPITATES FROM SAID SOLUTION WHILE THE ACID SALT OF THE OTHER BASE REMAINS IN SOLUTION.
Claim 2
Dependent Claim
90 words
THE PROCESS FOR SEPARATING L- AND D-AMINOMETHYL(3,4-DIHYDROXYPHENYL)-CARBINOL FROM AN EQUIMOLECULAR MIXTURE OF SAID BASES, WHICH COMPRISES HEATING SAID MIXTURE OF BASES ON THE STEAM BATH WITH AN ACID SELECTED FROM THE GROUP CONSISTING OF L-MANDELIC ACID AND D-MANDELIC ACID IN AN AHYDROUS LOWER ALKYL ALCOHOL TO THEREBY FORM SALTS OF SAID BASES WITH SAID ACID WHICH SALTS DISSOLVE IN SAID ALCOHOL, AND THEREAFTER COOLING SAID SOLUTION WHEREBY THE ACID SALT OF ONE OF SAID BASES PRECIPITATES FROM SAID SOLUTION WHILE THE ACID SALT OF THE OTHER BASE REMAINS IN SOLUTION.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-20 | 1961-07-22 | 1962-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-20 | 1965-07-22 | 1966-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-20 | 1969-07-22 | 1970-01-21 | $7700.00 | Window Closed / Lapsed |