Trifluoroacetaldehyde, trifluoroethanal, or fluoral,Trifluoroacetaldehyde, Peter Lin (2003), DOI:10.1002/047084289X.RN00213 is a fluorinated derivative of acetaldehyde with the formula . It is a gas at room temperature. Fluoral is used to introduce trifluoromethyl groups into organic compounds.2. Aldehydes, Fluorocarbon and Related Chemistry: Volume 2 (2007) Royal Society of Chemistry. It is highly electrophilic and forms a hydrate upon contact with water like other halogenated acetaldehydes.Kitazume, T., Yamazaki, T. (2019). Experimental Methods in Organic Fluorine Chemistry It is commonly used in form of ethyl hemiacetal (1-ethoxy-2,2,2-trifluoroethanol, ) due to the aldehyde's tendency to polymerise.Trifluoroacetaldehyde: A useful industrial bulk material for the synthesis of trifluoromethylated amino compounds, Hideyuki Mimura, Kosuke Kawada, Tetsuya Yamashita, Takeshi Sakamoto, Yasuo Kikugawa. Journal of Fluorine Chemistry Volume 131, Issue 4, April 2010, Pages 477-486
Synthesis and reactions Upon storage, fluoral polymerises into a waxy, white solid that is soluble in diethyl ether and acetone but not water and chlorocarbons. Heating of this polymer gives monomeric fluoral.Oxidative Nitration of 1,1,1-Trifluoropropane. Trifluoroacetaldehyde, Harold Shechter and Franklin Conrad, in J. Am. Chem. Soc. 1950, 72, 8, 3371–3373 Fluoral can be prepared from trifluoroacetic acid with lithium aluminium hydride in diethyl ether:
or with concentrated sulfuric acid.
Cathodic reduction of bromotrifluoromethane in dimethylformamide with aluminium as anode gives high yields of fluoral. In this reaction, DMF acts both as the solvent and the formylation agent.Advances in Electron Transfer Chemistry. (1999) Vapour-phase oxidation of trifluoroethanol also gives fluoral.
Photolysis of fluoral gives fluoroform, hexafluoroethane and carbon monoxide, along with some hydrogen.The photolysis of trifluoroacetaldehyde R. E. Dodd and J. Watson Smith, J. Chem. Soc., 1957, 1465-1473 https://doi.org/10.1039/JR9570001465
One known drug use of fluoral is in the synthesis LGD-2226.
See also Chloral Bromal Iodal
References