Enol ethyl acetoacetate E/Z type derivatives and synthesis and preparation method thereof

Abstract

The invention relates to enol ethyl acetoacetate E / Z type derivatives and a synthesis and preparation method thereof. The derivatives have the two chemical structural formulas described in the description. The preparation method of the compounds comprises that excessive ethyl acetoacetate and 4-fluorobenzoyl chloride are adopted, and the two novel enol ethyl acetoacetate E / Z type derivatives are generated through a nucleophilic substitution reaction of the raw materials under an alkaline condition; the preparation method comprises the following specific preparation process and steps: firstly simultaneously adding ethyl acetoacetate, pyridine and chloroform in a 50 mL round-bottom flask, connecting and adding a constant-pressure dropping funnel containing 4-fluorobenzoyl chloride at a flask mouth, fixing the round-bottom flask on a magnetic stirrer, turning on a stirring switch, at the moment, spinning a dropping funnel stopcock, dropping 4-fluorobenzoyl chloride slowly, and carrying out a reaction; after the dropping is finished, continuing the reaction; and after the reaction is finished, washing with distilled water for tens of times in a separating funnel, drying and distilling, spreading the obtained liquid with a silica gel TLC, scraping a strip silica gel which shows yellow green under fluorescent light, extracting with chloroform, stirring to dissolve and distilling, and thus obtaining a little product at the bottle bottom.

Description

technical field [0001] The invention relates to two novel enol E / Z derivatives of ethyl acetoacetate and their synthesis and preparation methods. Background technique [0002] Dicarbonyl compounds are compounds containing two carbonyl groups in the molecule, and the compound with a methylene group between the two carbonyl groups is called β-dicarbonyl compound. β-dicarbonyl compounds include β-keto esters, β-keto acids, β-diketones, and β-carbonyl amides. The α-H of β-dicarbonyl compounds is affected by two carbonyl groups, so it has special activity, and the most common phenomenon is the coexistence of keto-enol equilibrium. Since the carbonyl compound has an acidic α proton, it will undergo proton transfer at different pH to form a keto form and an enol form, so it can be interconverted by acid or base catalysis. [0003] Ethyl acetoacetate, also known as ethyl acetoacetate, is a typical β-dicarbonyl compound, an equilibrium system composed of a ketone structure and an e...

AI Technical Summary

Problems solved by technology

The above factors mainly affect the ability of enol molecules to form intramolecular hydrogen bonds, thereby affecting the stability of their structures

Images