← Back to Patent Explorer
US2503385A Expired / Lapsed US ⏱️ 0.0 years remaining

Production of 7-dehydrosterol esters

Assignee: Nopco Chemical Co
•
Filing: 1948-04-14
•
Granted: 1950-04-11
•
Expires: 1968-04-14
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

No abstract record available.

Inventors

  • 👤 David H Gould

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 01:30
CPC Classifications
C; C07; C07J; C07J9/00; C07J75/00

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 72 words
A PROCESS FOR IMPROVING THE PURITY, PHYSICAL APPEARANCE AND CRYSTALLINE NATURE OF AN ESTER OF A 7-DEHYDROSTEROL WHICH COMPRISES ADMIXING AN ESTER OF A 7-DEHYDROSTEROL WITH AT LEAST TWO VOLUMES OF A SATURATED ALIPHATIC HYDROCARBON SOLVENT CONTAINING FROM FOUR TO SEVEN CARBON ATOMS, SAID SOLVENT BEING AT A TEMPERATURE AT LEAST AS LOW AS ABOUT 0*C., AND THEN SEPARATING SAID SOLVENT FROM THE ESTER OF THE 7-DEHYDROSTEROL BY MEANS OTHER THAN EVAPORATION.
Claim 2
Dependent Claim 72 words
A PROCESS FOR IMPROVING THE PURITY, PHYSICAL APPEARANCE AND CRYSTALLINE NATURE OF AN ESTER OF A 7-DEHYDROSTEROL WHICH COMPRISES ADMIXING AN ESTER OF A 7-DEHYDROSTEROL WITH AT LEAST TWO VOLUMES OF A SATURATED ALIPHATIC HYDROCARBON SOLVENT CONTAINING FROM FOUR TO SEVEN CARBON ATOMS, SAID SOLVENT BEING AT A TEMPERATURE AT LEAST AS LOW AS ABOUT 0*C., AND THEN SEPARATING SAID SOLVENT FROM THE ESTER OF THE 7-DEHYDROSTEROL BY MEANS OTHER THAN EVAPORATION.

References Cited (Backward Citations)

US2266674A Cited
US2173629A Cited
US2441091A Cited
GB574432A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1953-04-10 1953-10-10 1954-04-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1957-04-10 1957-10-10 1958-04-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1961-04-10 1961-10-10 1962-04-11 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag