US2810870A
Expired / Lapsed
US
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Switching transistor
Assignee: International Business Machines Corp
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Filing: 1955-11-22
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Granted: 1957-10-22
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Expires: 1975-11-22
Abstract
Abstract 3R-Phthalimido-1-(1'S-p-nitrobenzyloxycarbonyl-2'-methylprop-2'-enyl)- 4-oxo-2-azetidinesulfenic acid is prepared by scission of the S-C2 bond of p-nitrobenzyl 6-phthalimido-2,2-dimethylpenam-3-carboxylate-1-oxide. The sulfenic acid can be converted to desacetoxycephalosporin.
Inventors
- 👤 Lloyd P Hunter
- 👤 Richard F Rutz
- 👤 Gardiner L Tucker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:45
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/70; H10D; H10D99/00; H10P; H10P14/00; H10P14/40; H10P14/46; H10P14/47; H10P95/00; H10W72/00; H10W72/30; H10W76/00; H10W76/10; H10W76/12; H10W76/161; H10W72/071; H10W72/075; H10W72/07551; H10W72/07554; H10W72/50; H10W72/851; H10W72/874; H10W72/884; H10W72/90; H10W72/951; Y; Y10; Y10S; Y10S205/00; Y10S205/917; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528; Y10T428/12639; Y10T428/12646; Y10T428/12674; Y10T428/12708; Y10T428/12722
Claims Analysis
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References Cited (Backward Citations)
US2681993A
Cited
US2692839A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-21 | 1961-04-22 | 1961-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-21 | 1965-04-22 | 1965-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-21 | 1969-04-22 | 1969-10-22 | $7700.00 | Window Closed / Lapsed |