Diketene is a colorless liquid produced by dimerization of ketene. It is a highly reactive building block which can be combined with numerous other chemical compounds to make a wide range of products. Because of its high energy content, transport of diketene is forbidden. It is processed further at the site of manufacture. Lonza is one of the world’s leading suppliers of diketene derivatives manufactured in its production facility in Visp, Switzerland. Our diketene derivatives are used in the pharmaceutical, vitamin, agrochemical and pigment industries. The niche markets are in cosmetics, plasticizers, paints. The acetoacyl group in diketene derivatives has a broad functionality which can be used for the production of further products. Lonza’s most comprehensive diketene product lines are those made with alcohols (aceto-acetic acid and acrylate derivatives), aliphatic amines (alkylamides) and aromatic amines (arylamides). Lonza uses some of these to produce further components (pyrazolones, aminocrotonates, side chains).
The following summary provides an overview of the diketene derivative product groups:
Diketene esters (acetoacetates): “Major” products such as methyl, ethyl, isopropylester of acetoacetic acid are produced in a continuous process and purified by distillation. “Minor” derivatives are produced batchwise in stirred vessel reactors. The products are used mostly in the dye, agrochemical, pharmaceutical and vitamin industries.
Alkylamides: Aliphatic amines react with diketene to result in alkylamides. Major products such as monomethyl- or dimethylacetoacetamides are manufactured as aqueous solutions with continuous processes; other derivatives and water-free compounds are produced with batch processes. The (alkyl-) acetoacetamides are used principally in the manufacture of insecticides. The derivatives are also deployed in the pigment, pharmaceutical and polymer industries.
DHS / NaDHS: The catalytic dimerization of diketene yields dehydroacetic acid (DHS), which is a solid material. The free acid can be neutralized with sodium hydroxide and is available as the salt NaDHS or its monohydrate NaDHS-H2O. These products are used above all in the manufacture of PVC stabilizers and as preservatives in the cosmetic industries.
Other diketene derivatives: 4-Chloroacetoacetic acid ester is a highlyversatile diketene derivative. It can be used in syntheses of various pharmaceutical intermediates.
Ketene: Lonza has the specific capability to perform a variety of reactions with ketene. The production of ethyl 4, 4, 4-trifluoroacetoacetate is one example for such a ketene reaction.