Patent ID: 8273904

Claim:
A process for preparing a 4-aminobut-2-enolide compound of formula (I) comprising reacting a compound of formula (II) with an amine of formula (III) where R 1 is hydrogen, alkyl, fluoroalkyl, alkenyl, fluoroalkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, fluorocycloalkyl, alkoxy, alkoxyalkyl, fluorocycloalkylalkyl or arylalkyl; R 2 is alkyl, aryl or arylalkyl; Z is hydrogen, an alkali metal or an alkaline earth metal; A is pyrid-2-yl or pyrid-4-yl, or is pyrid-3-yl which is optionally 6-substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl or trifluoromethoxy, or is in which X is halogen, alkyl or fluoroalkyl, and Y is halogen, alkyl, fluoroalkyl, or fluoroalkoxy.