2-Ethyl-2-oxazoline oxazolines towards ring-opening by chloride ions during protonation of the imine nitrogen. The direct reaction of propanoyl chloride with 2-chloroethylamine hydrochloride in the presence of triethylamine avoids the formation of water. Propanal reacts with 2-aminoethanol in "t"-butanol to 2-ethyl-2-oxazoline in the presence of the iodinating reagent 1,3-diiodo-5,5-dimethylhydantoin (DIH) and potassium carbonate. 2-Ethyl-2-oxazoline is a readily water-soluble, colorless liquid which is also soluble in a variety of organic solvents and possesses an amine-like smell. Aqueous solutions react alkaline. The compound is stable in alkaline but hydrolyses under acid action. In anhydrous form, 2-ethyl-2-oxazoline is mostly used as a monomer. The cationic
Ethyl acetoacetate a bidentate ligand. For example, it forms purple coordination complexes with iron(III) salts: Ethyl acetoacetate can also be reduced to ethyl 3-hydroxybutyrate. Ethyl acetoacetate, when heated alone (uncatalyzed) with benzyl alcohol, forms synthetically useful benzyl acetoacetate (benzyl groups being easily removed later by catalytic hydrogenolysis over Pd/C under neutral conditions), via a mechanism involving acetylketene. Ethyl (and other) acetoacetates nitrosate readily with equimolar sodium nitrite in acetic acid, to afford the corresponding oximinoacetoacetate esters. A dissolving-zinc reduction of these in acetic acid in the presence of ketoesters or beta-diketones constitute the Knorr synthesis of pyrroles, useful for porphyrin synthesis. Ethyl