|Preferred IUPAC name
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||140.182 g·mol−1|
|Appearance||Colorless or white solid|
|Melting point||112–115 °C (234–239 °F; 385–388 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
2,2,4,4-Tetramethylcyclobutanedione is the organic compound with the formula (CH3)4C4O2. The compound is a diketone of cyclobutane, bearing four methyl groups. It is a white solid that is used as a precursor to diverse industrial products.
Synthesis and reactions
2,2,4,4-Tetramethylcyclobutanedione is the head-to-tail dimer of dimethylketene. It arises spontaneously when dimethylketene is produced by dehydrohalogenation of isobutyryl chloride with triethylamine.
The 2,2,4,4-tetramethylcyclobutanedione isomerizes to the lactone called dimethylketene dimer (4-isopropylidene-3,3-dimethyl-2-oxetanone). Dimethylketene dimer is a precursor to various alkyl ketene dimers, which are used in papermaking.