Patent US2925568A successfully refreshed from Google Patents.
Patent US4309362A successfully refreshed from Google Patents.
US4309362A
Expired / Lapsed
US
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Process for the optical resolution of DL-p-hydroxy-phenylglycine
Assignee: Tanabe Pharma Corp
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Filing: 1978-03-13
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Granted: 1982-01-05
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Expires: 1998-03-13
Abstract
Abstract Seed crystals of an optically active enantiomer of any one of p-hydroxyphenylglycine benzenesulfonate, p-hydroxyphenylglycine p-ethylbenzenesulfonate, p-hydroxyphenylglycine o-toluenesulfonate or p-hydroxyphenylglycine sulfosalicylate are added to a supersaturated solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt. Crystallization of the optically active enantiomer results. Then, the crystals are recovered. Alternatively, crystals of the optically active enantiomer may be added to a hot solution of the racemic modification of the corresponding p-hydroxyphenylglycine salt to produce a supersaturated solution thereof. The solution is then cooled to crystallize out the optically active enantiomer. Optically active p-hydroxyphenylglycine benzenesulfonate, optically active p-hydroxyphenylglycine p-ethylbenzenesulfonate, optically active p-hydroxyphenylglycine o-toluenesulfonate or optically active p-hydroxyphenylglycine sulfosalicylate is thereby obtained.
Inventors
- 👤 Ichiro Chibata
- 👤 Shigeki Yamada
- 👤 Chikara Hongo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:16
CPC Classifications
C; C07; C07C; C07C309/00; C07C309/01; C07C309/28; C07C309/29; C07C309/30; C07B; C07B2200/00; C07B2200/07
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
88 words
A process for resolving a racemic modification selected from the group consisting of DL-p-hydroxyphenylglycine benzenesulfonate , DL-p-hydroxyphenylglycine p-ethylbenzenesulfonate, DL-p-hyroxyphenylglycine o-toluenesulfonate and DL-p-hyroxyphenylglycine sulfosalicylate which comprises preparing a supersaturated solution of said racemic modification in an inert solvent therefore, adding crystals of a desired enantiomer of said modification to the solution before and/or after said solution reaches the condition of supersaturation so that the proportion of one of the enantiomers becomes greater than that of the other enantiomer, allowing crystallization to take place, and recovering the separated crystals therefrom.
Claim 2
Dependent Claim
88 words
A process for resolving a racemic modification selected from the group consisting of DL-p-hydroxyphenylglycine benzenesulfonate , DL-p-hydroxyphenylglycine p-ethylbenzenesulfonate, DL-p-hyroxyphenylglycine o-toluenesulfonate and DL-p-hyroxyphenylglycine sulfosalicylate which comprises preparing a supersaturated solution of said racemic modification in an inert solvent therefore, adding crystals of a desired enantiomer of said modification to the solution before and/or after said solution reaches the condition of supersaturation so that the proportion of one of the enantiomers becomes greater than that of the other enantiomer, allowing crystallization to take place, and recovering the separated crystals therefrom.
Claim 3
Dependent Claim
18 words
The process of claim 1 in which said racemic modification is DL-p-hyroxyphenylglycine benzenesulfonate, DL-p-hydroxyphenylglycine p-ethylbenzenesulfonate or DL-p-hydroxyphenylglycine o-toluenesulfonate.
Claim 4
Dependent Claim
13 words
The process of claim 1 in which said racemic modification is DL-p-hyroxyphenylglycine o-toluenesulfonate.
Claim 5
Dependent Claim
38 words
The process of claim 1 in which said inert solvent is water, an alkanol of one to six carbon atoms, an alkanone of three to six carbon atoms or a mixture of water and said alkanol or alkanone.
Claim 6
Dependent Claim
38 words
The process of claim 2 in which said inert solvent is water, an alkanol of one to six carbon atoms, an alkanone of three to six carbon atoms or a mixture of water and said alkanol or alkanone.
Claim 7
Dependent Claim
38 words
The process of claim 3 in which said inert solvent is water, an alkanol of one to six carbon atoms, an alkanone of three to six carbon atoms or a mixture of water and said alkanol or alkanone.
Claim 8
Dependent Claim
23 words
The process of claim 1 in which the desired enantiomer is inoculated as seed crystals to the supersaturated solution of the racemic modification.
Claim 9
Dependent Claim
23 words
The process of claim 2 in which the desired enantiomer is inoculated as seed crystals to the supersaturated solution of the racemic modification.
Claim 10
Dependent Claim
23 words
The process of claim 3 in which the desired enantiomer is inoculated as seed crystals to the supersaturated solution of the racemic modification.
Claim 11
Dependent Claim
29 words
The process of claim 1 in which the desired enantiomer is dissolved in a solution of the racemic modification and the solution is cooled to produce a supersaturated solution.
Claim 12
Dependent Claim
29 words
The process of claim 2 in which the desired enantiomer is dissolved in a solution of the racemic modification and the solution is cooled to produce a supersaturated solution.
Claim 13
Dependent Claim
29 words
The process of claim 3 in which the desired enantiomer is dissolved in a solution of the racemic modification and the solution is cooled to produce a supersaturated solution.
Claim 14
Dependent Claim
36 words
The process of claim 1 in which the desired enantiomer is dissolved in a solution of the racemic modification, and the solution is allowed to cool and is inoculated with the desired enantiomer as seed crystals.
Claim 15
Dependent Claim
36 words
The process of claim 2 in which the desired enantiomer is dissolved in a solution of the racemic modification, and the solution is allowed to cool and is inoculated with the desired enantiomer as seed crystals.
Claim 16
Dependent Claim
36 words
The process of claim 3 in which the desired enantiomer is dissolved in a solution of the racemic modification, and the solution is allowed to cool and is inoculated with the desired enantiomer as seed crystals.
Claim 17
Dependent Claim
47 words
The process of claim 1 in which additional racemic modification is dissolved in the mother liquor obtained after the recovery of the desired enantiomer, at an elevated temperature thus producing another supersaturated solution, a small amount of the other enantiomer are allowed to separate out and recovered.
Claim 18
Dependent Claim
28 words
The process of claim 16 wherein said process is repeated a plurality of times whereby said optically active enantiomers are successively and alternatively separated from said racemic modification.
References Cited (Backward Citations)
US3994962A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-04 | 1985-07-06 | 1986-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-04 | 1989-07-06 | 1990-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-04 | 1993-07-06 | 1994-01-05 | $7700.00 | Window Closed / Lapsed |