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US3840591A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the production of p-nitrotoluene-2-sulfonic acid

Assignee: Novartis Corp
•
Filing: 1973-04-25
•
Granted: 1974-10-08
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Expires: 1993-04-25
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Abstract

Abstract 1. A PROCESS FOR THE PRODUCTION OF P-NITROTOLUENE-2-SULFONIC ACID, WHICH COMPRISES (A) INTIMATELY CONTACTING MOLTEN P-NITROTOLUENE WITH A MIXTURE OF AT MOST 50% BY VOLUME OF GASEOUS SULFUR TRIOXIDE AND AN INERT GAS AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 90 TO 150* C., THE SULFUR TRIOXIDE BEING USED IN ABOUT 1 TO 15% MOLAR EXCESS OVER THE P-NITROTOLUENE EMPLOYED, (B) ADDING WATER TO THE REACTION MIXTURE SO AS TO OBTAIN AN AQUEOUS SLURRY CONTAINING ABOUT 20 TO 50% OF DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, (C) MAINTAINING SAID SLURRY AT A TEMPERATURE RANGING FROM ABOUT 80 TO 100* C. FOR ABOUT 15 TO 60 MINUTES TO HYDROLYZE THE P-NITROLUENE-2-SULFONIC ACID ANHYDRIDE FORMED DURING THE SULFONATION IN ADMIXTURE WITH P-NITROTOLUENE-2-SULFONIC ACID AND CONVERT IT TO P-NITROTOLUENE-2-SULFONIC ACID, (D) SEPARATING THE WATER-INSOLUBLE BY-PRODUCTS FROM THE SOLUTION CONTAINING THE DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, AND (E) TREATING THE SEPARATED P-NITROTOLUENE-2-SULFONIC ACID SOLUTION WITH ACTIVATED CARBON TO REMOVE DISSOLVED COLOR BODIES AND DISSOLVED UNREACTED P-NITROTOLUENE AND TO OBTAIN SUBSTANTIALLY PURE P-NITROTOLUENE-2-SULFONIC ACID IN SOLUTION.

Inventors

  • 👤 J Lee
  • 👤 R Eckert
  • 👤 R Miller

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 05:30
CPC Classifications
C; C07; C07C; C07C303/00; C07C303/02; C07C303/04; C07C303/06

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 167 words
A PROCESS FOR THE PRODUCTION OF P-NITROTOLUENE-2-SULFONIC ACID, WHICH COMPRISES (A) INTIMATELY CONTACTING MOLTEN P-NITROTOLUENE WITH A MIXTURE OF AT MOST 50% BY VOLUME OF GASEOUS SULFUR TRIOXIDE AND AN INERT GAS AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 90 TO 150* C., THE SULFUR TRIOXIDE BEING USED IN ABOUT 1 TO 15% MOLAR EXCESS OVER THE P-NITROTOLUENE EMPLOYED, (B) ADDING WATER TO THE REACTION MIXTURE SO AS TO OBTAIN AN AQUEOUS SLURRY CONTAINING ABOUT 20 TO 50% OF DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, (C) MAINTAINING SAID SLURRY AT A TEMPERATURE RANGING FROM ABOUT 80 TO 100* C. FOR ABOUT 15 TO 60 MINUTES TO HYDROLYZE THE P-NITROLUENE-2-SULFONIC ACID ANHYDRIDE FORMED DURING THE SULFONATION IN ADMIXTURE WITH P-NITROTOLUENE-2-SULFONIC ACID AND CONVERT IT TO P-NITROTOLUENE-2-SULFONIC ACID, (D) SEPARATING THE WATER-INSOLUBLE BY-PRODUCTS FROM THE SOLUTION CONTAINING THE DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, AND (E) TREATING THE SEPARATED P-NITROTOLUENE-2-SULFONIC ACID SOLUTION WITH ACTIVATED CARBON TO REMOVE DISSOLVED COLOR BODIES AND DISSOLVED UNREACTED P-NITROTOLUENE AND TO OBTAIN SUBSTANTIALLY PURE P-NITROTOLUENE-2-SULFONIC ACID IN SOLUTION.
Claim 2
Dependent Claim 167 words
A PROCESS FOR THE PRODUCTION OF P-NITROTOLUENE-2-SULFONIC ACID, WHICH COMPRISES (A) INTIMATELY CONTACTING MOLTEN P-NITROTOLUENE WITH A MIXTURE OF AT MOST 50% BY VOLUME OF GASEOUS SULFUR TRIOXIDE AND AN INERT GAS AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 90 TO 150* C., THE SULFUR TRIOXIDE BEING USED IN ABOUT 1 TO 15% MOLAR EXCESS OVER THE P-NITROTOLUENE EMPLOYED, (B) ADDING WATER TO THE REACTION MIXTURE SO AS TO OBTAIN AN AQUEOUS SLURRY CONTAINING ABOUT 20 TO 50% OF DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, (C) MAINTAINING SAID SLURRY AT A TEMPERATURE RANGING FROM ABOUT 80 TO 100* C. FOR ABOUT 15 TO 60 MINUTES TO HYDROLYZE THE P-NITROLUENE-2-SULFONIC ACID ANHYDRIDE FORMED DURING THE SULFONATION IN ADMIXTURE WITH P-NITROTOLUENE-2-SULFONIC ACID AND CONVERT IT TO P-NITROTOLUENE-2-SULFONIC ACID, (D) SEPARATING THE WATER-INSOLUBLE BY-PRODUCTS FROM THE SOLUTION CONTAINING THE DISSOLVED P-NITROTOLUENE-2-SULFONIC ACID, AND (E) TREATING THE SEPARATED P-NITROTOLUENE-2-SULFONIC ACID SOLUTION WITH ACTIVATED CARBON TO REMOVE DISSOLVED COLOR BODIES AND DISSOLVED UNREACTED P-NITROTOLUENE AND TO OBTAIN SUBSTANTIALLY PURE P-NITROTOLUENE-2-SULFONIC ACID IN SOLUTION.

References Cited (Backward Citations)

US2892866A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-10-07 1978-04-08 1978-10-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-10-07 1982-04-08 1982-10-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-10-07 1986-04-08 1986-10-08 $7700.00 Window Closed / Lapsed

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