Process for the preparation of N,N' -carbonylbislactams
AssigneeSnpe
InventorsHubert Bonnard, Laurence Ferruccio, Jean-Pierre Senet, Pierre-Yves Le Roy
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Abstract
The invention relates to a process for the preparation of N,N′-carbonylbislactams by reaction of phosgene with at least one lactam which is characterized in that the tertiary amine is chosen from the group consisting of non-nucleophilic aliphatic tertiary amines. N,N′-Carbonylbislactams of high purity are thus obtained with good yields, both in the laboratory and on the industrial scale.
Claims12
Process for the preparation of N,N′-carbonylbislactams by reaction of phosgene with at least one lactam in the presence of a tertiary amine, characterized in that the tertiary amine is chosen from the group consisting of non-nucleophilic aliphatic tertiary amines.
Process according to any one of the preceding claims, characterized in that the amine is diisopropylethylamine.
Process according to any one of the preceding claims, characterized in that phosgene is introduced into the reaction medium at a temperature of between approximately −10° C. and approximately +5° C.
Process according to any one of the preceding claims, characterized in that, after the introduction of the phosgene, the reaction mixture is heated at a temperature of between approximately 40° and approximately 50° C.
Process according to any one of the preceding claims, characterized in that the reaction is carried out in a solvent chosen from solvents with a melting point below approximately −10° C.
Process according to the preceding claim, characterized in that the amount of base added is such that the final pH is approximately 13.
Process according to any one of the preceding claims, characterized in that the N,N′-carbonylbislactam is recovered by crystallization from water.
Process according to any one of the preceding claims, characterized in that the N,N′-carbonylbislactam is purified by washing with an alcohol.
Dependencies are inferred from the claim text.