2,2,4,4-Tetrarnethyl-l,3-~yclobutanedione (I) has been shown to participate in ring opening reactions with a variety of bases. Alkyl amines and ammonia react to form their respective 2,2,4-trimethyl-3-oxovaleramides in yields up to 80% (2,3). Hydrazine reacts with the dione to give ring opening, followed by condensation to yield 4,4dimethyl-3-isopropyl-2-pyrazolin-5-one (2).With acid catalysis, weaker bases such as aniline condense to form Schiff bases (2).The basicity of aziridines, with pKa values of approximately 8.0, is intermediate between the pKa values of amines which cause ring opening reactions (i.e. ethyl amine, pKa = 10.75) and amines which yield carbonyl condensation products (i.e. aniline, pKa = 4.58) with
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.