Diketene also reacts with alcohols and amines to the corresponding acetoacetic acid derivatives. The process is sometimes called acetoacetylation. An example is the reaction with 2-aminoindane:[6]
Diketene is an important industrial intermediate used for the production of acetoacetate esters and amides as well as substituted 1-phenyl-3-methylpyrazolones. The latter are used in the manufacture of dyestuffs and pigments.[7] A typical reaction is:
Diketenes with two alkyl chains are used in the manufacture of paper for sizing of paper in order to improve their printability (byhydrophobization). Besides the rosin resins with about 60% share of world consumption, long chain diketenes called alkylketene dimers (AKD) are with 16% share the most important synthetic paper sizes, they are usually used in concentrations of 0.15%, meaning 1.5 kg solid AKD/t paper.
The preparation of AKD is carried out by chlorination of long chain fatty acids (such as stearic acid, using chlorinating agents such as thionyl chloride) to give the corresponding acid chlorides and subsequent elimination of HCl by amines (for example triethylamine) in toluene or other solvents:[9]
Exemplary for the synthesis of arylides by the reaction of diketenes with aromatic amines is:
Aromatic diazonium coupling with arylides to form azo dyes, such as Pigment Yellow 74:
The industrial synthesis of the sweetener acesulfam-K is based on the reaction of diketene with sulfamic acid and cyclization by sulfur trioxide (SO3).[10]
^Rafael Gómez-Bombarelli; Marina González-Pérez; María Teresa Pérez-Prior; José A. Manso; Emilio Calle; Julio Casado (2008). "Kinetic Study of the Neutral and Base Hydrolysis of Diketene". J. Phys. Org. Chem.22 (5): 438–442. doi:10.1002/poc.1483.
^Kiran Kumar Solingapuram Sai; Thomas M. Gilbert; Douglas A. Klumpp (2007). "Knorr Cyclizations and Distonic Superelectrophiles". J. Org. Chem.72 (25): 9761–9764. doi:10.1021/jo7013092. PMID17999519.
^Ashford's Dictionary of Industrial Chemicals, Third Edition, 2011, pages 3241-2.
^EP 0218076 Process for the preparation of the non-toxic salts of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-on-2,2-dioxide.
^Rafael Gómez-Bombarelli; Marina González-Pérez; María Teresa Pérez-Prior; José A. Manso; Emilio Calle; Julio Casado (2008). "Chemical Reactivity and Biological Activity of Diketene". Chem. Res. Toxicol.21 (10): 1964–1969. doi:10.1021/tx800153j. PMID18759502.