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US3823140A Expired / Lapsed US ⏱️ 0.0 years remaining

Delta 3-4-carboxy-3-oxobutyl cephalosporins

Assignee: Glaxo Laboratories Ltd
•
Filing: 1971-03-23
•
Granted: 1974-07-09
•
Expires: 1991-03-23
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Abstract

Abstract THE INVENTION IS CONCERNED WITH &3-4-CARBOXYL CEPHALOSPORIN ANTIBIOTICS POSSESSING A 3-OXOBUTYL GROUP AT THE 3-POSITION. THE INVENTION ALSO DESCRIBES PROCESSES FOR THE PREPARATION OF SUCH COMPOUNDS.

Inventors

  • 👤 J Clark
  • 👤 W Underwood

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 08:15
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/14; C07D501/16; C07D501/20; C07D501/24

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-07-08 1978-01-07 1978-07-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-07-08 1982-01-07 1982-07-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-07-08 1986-01-07 1986-07-09 $7700.00 Window Closed / Lapsed

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