Patent US3956304A successfully refreshed from Google Patents.
US3956304A
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Preparation of 2-methyl-4-isopropylidene-2-oxazolin-5-one
Assignee: Evonik Operations GmbH
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Filing: 1974-09-12
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Granted: 1976-05-11
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Expires: 1994-09-12
Abstract
Abstract N-acetyl-DL-penicillamine is prepared from DL-valine by converting the DL-valine into 2-methyl-4-isopropylidene-2-oxazolin-5-one using chloroacetyl chloride at 50° to 150°C. and then converting the 2-methyl-4-isopropylidene-2-oxazolin-5-one into the N-acetyl-DL-penicillamine.
Inventors
- 👤 Werner Schwarze
- 👤 Gerd Schreyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:29
CPC Classifications
C; C07; C07D; C07D263/00; C07D263/02; C07D263/30; C07D263/34; C07D263/36; C07D263/42
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
39 words
A process for the production of 2-methyl-4-isopropylidene-2-oxazolin-5-one in a single step comprising reacting DL-valine with chloroacetyl chloride at a temperature between about 50° and 150°C., there being employed at least 1 mole of chloroacetyl chloride per mole of valine.
Claim 2
Dependent Claim
39 words
A process for the production of 2-methyl-4-isopropylidene-2-oxazolin-5-one in a single step comprising reacting DL-valine with chloroacetyl chloride at a temperature between about 50° and 150°C., there being employed at least 1 mole of chloroacetyl chloride per mole of valine.
Claim 3
Dependent Claim
14 words
A process according to claim 1, wherein the temperature is between 70° and 120°C.
Claim 4
Dependent Claim
17 words
A process according to claim 2, wherein the reaction is carried out in an inert organic solvent.
Claim 5
Dependent Claim
18 words
A process according to claim 3, wherein an inert gas is passed through the mixture during the reaction.
Claim 6
Dependent Claim
21 words
A process according to claim 4, wherein there are used at least 2 moles of chloroacetyl chloride per mole of valine.
Claim 7
Dependent Claim
21 words
A process according to claim 5 wherein there are used 2 to 4 moles of chloroacetyl chloride per mole of valine.
Claim 8
Dependent Claim
16 words
A process according to claim 1, wherein the reaction is carried out in an organic solvent.
Claim 9
Dependent Claim
21 words
A process according to claim 7 wherein there is employed at least 1.8 moles of chloroacetyl chloride per mole of valine.
Claim 10
Dependent Claim
21 words
A process according to claim 8 wherein there are used 1.8 to 4 moles of chloroacetyl chloride per mole of valine.
Claim 11
Dependent Claim
20 words
A process according to claim 1 wherein 1 to 4 moles of chloroacetyl chloride are employed per mole of valine.
Claim 12
Dependent Claim
26 words
A process according to claim 1 wherein the process consists essentially of reacting the DL-valine with chloroacetyl chloride at a temperature between about 50° and 150°C.
Claim 13
Dependent Claim
21 words
A process according to claim 11 wherein there are employed at least 1.8 moles of chloroacetyl chloride per mole of valine.
Claim 14
Dependent Claim
18 words
A process according to claim 12 wherein an inert gas is passed through the mixture during the reaction.
References Cited (Backward Citations)
US2569801A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |