Improved process for preparing 1, 5-pentamethylene diisocyanate from 1, 5-pentamethylene diamine salts

The present application describes an improved process for the preparation of 1, 5-pentamethylene diisocyanate (PDI) from a 1, 5-pentamethylene diamine salt. The method generally includes: providing a solution comprising a 1, 5-pentamethylene diamine salt dissolved in an inert solvent in the presence...

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Bibliographic Details
Main Authors QIU GUISEN, LIU WENJIE, LU CHENGLIANG
Format Patent
LanguageChinese
English
Published 12.04.2022
Subjects
ACYCLIC OR CARBOCYCLIC COMPOUNDS
CHEMISTRY
METALLURGY
ORGANIC CHEMISTRY
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Summary:The present application describes an improved process for the preparation of 1, 5-pentamethylene diisocyanate (PDI) from a 1, 5-pentamethylene diamine salt. The method generally includes: providing a solution comprising a 1, 5-pentamethylene diamine salt dissolved in an inert solvent in the presence of a tertiary amine; and subjecting the solution to a liquid phase phosgenation reaction to convert 1, 5-pentanediamine to PDI. The phosgenation reaction includes the step of maintaining the reaction at a temperature of 100 DEG C to 120 DEG C for a sufficient time to achieve a desired PDI threshold yield. The process described herein enables a reduction in the amount of reactants consumed, a reduction in reaction temperature, and/or a reduction in total reaction time compared to conventional phosgenation reactions. It was found that the use of bio-based 1, 5-pentanediamine salts that have not previously been distilled is advantageous because the subjecting of 1, 5-pentanediamine to elevated temperatures results in
Bibliography:Application Number: CN202111178208