Abstract 1. A PROCESS FOR THE RECOVERY IN PURIFIED FORM OF PAMINOPHENOL PREPARED BY CATALYTIC REDUCTION OF NITROBENZENE IN ACID MEDIUM WHEREBY ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE PRESENT AS IMPURITIES, WHICH PROCESS COMPRISES CONTACTING A SOLUTION OF P-AMINOPHENOL AND SAID IMPURITIES IN AN AQUEOUS MEDIUM HAVING A PH OF 5.0 TO 5.5-JUST SHORT OF THAT AT WHICH PRECIPITATION OF P-AMINOPHENOL OCCURS AND AT WHICH ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE IN THE FORM OF FREE BASES WITH AN EXYRACTION MEDIUM CONSISTING ESSENTIALLY OF A NON-OXYGENATED SOLVENT IMMISCIBLE WITH WATER WHICH SELECTIVELY DISSOLVES THE IMPURITIES, SEPARATING THE RESULTING PHASES WITH SAID P-AMINOPHENOL IN SOLUTION IN THE AQUEOUS PHASE AND RECOVERING P-AMINOPHENOL OF IMPROVED PURITY FROM THE AQUEOUS PHASE.
Inventors
👤 K Reid
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-29 20:50
CPC Classifications
C; C07; C07C; C07C213/00; C07C213/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
A PROCESS FOR THE RECOVERY IN PURIFIED FORM OF PAMINOPHENOL PREPARED BY CATALYTIC REDUCTION OF NITROBENZENE IN ACID MEDIUM WHEREBY ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE PRESENT AS IMPURITIES, WHICH PROCESS COMPRISES CONTACTING A SOLUTION OF P-AMINOPHENOL AND SAID IMPURITIES IN AN AQUEOUS MEDIUM HAVING A PH OF 5.0 TO 5.5-JUST SHORT OF THAT AT WHICH PRECIPITATION OF P-AMINOPHENOL OCCURS AND AT WHICH ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE IN THE FORM OF FREE BASES WITH AN EXYRACTION MEDIUM CONSISTING ESSENTIALLY OF A NON-OXYGENATED SOLVENT IMMISCIBLE WITH WATER WHICH SELECTIVELY DISSOLVES THE IMPURITIES, SEPARATING THE RESULTING PHASES WITH SAID P-AMINOPHENOL IN SOLUTION IN THE AQUEOUS PHASE AND RECOVERING P-AMINOPHENOL OF IMPROVED PURITY FROM THE AQUEOUS PHASE.
Claim 2
Dependent Claim
114 words
A PROCESS FOR THE RECOVERY IN PURIFIED FORM OF PAMINOPHENOL PREPARED BY CATALYTIC REDUCTION OF NITROBENZENE IN ACID MEDIUM WHEREBY ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE PRESENT AS IMPURITIES, WHICH PROCESS COMPRISES CONTACTING A SOLUTION OF P-AMINOPHENOL AND SAID IMPURITIES IN AN AQUEOUS MEDIUM HAVING A PH OF 5.0 TO 5.5-JUST SHORT OF THAT AT WHICH PRECIPITATION OF P-AMINOPHENOL OCCURS AND AT WHICH ANILINE AND 4,4''-DIAMINODIPHENYL ETHER ARE IN THE FORM OF FREE BASES WITH AN EXYRACTION MEDIUM CONSISTING ESSENTIALLY OF A NON-OXYGENATED SOLVENT IMMISCIBLE WITH WATER WHICH SELECTIVELY DISSOLVES THE IMPURITIES, SEPARATING THE RESULTING PHASES WITH SAID P-AMINOPHENOL IN SOLUTION IN THE AQUEOUS PHASE AND RECOVERING P-AMINOPHENOL OF IMPROVED PURITY FROM THE AQUEOUS PHASE.