Patent · US Expired

Process for the production of maleamic acids

US3947493A · kind A · utility

3Cited by
0References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 5, 1973
Grant dateMar 30, 1976
Priority date
Expiry dateOct 5, 1993

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07C233/34
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

PAC Maleamic acids of formula: ##EQU1## where R is a divalent organic radical and X is H or NHCOCH=CHCOOH are prepared in suspension as a flowing non-thixotropic fluid by a process wherein a solution of a primary monoamine or diamine in a solvent is run into a solution of maleic anhydride in a solvent in an amount such that there is an anhydride excess of 5 to 20 mol % relative to the theoretical amount necessary for the reaction with the amine, the mixture is agitated, the reaction temperature is 40.degree. to 130.degree.C., the time taken to run in the amine solution is at least 67 minutes, and the amine solution is run in at a rate such that the slope of the curve representing the variation, as a function of time, in the rate of running in as % of the total amount of amine solution employed per minute (acceleration) has, at every point on this curve, a value not greater than 0.044.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.