Reaction of Diketoesters of Perfluorodicarboxylic Acids with Alkyl Ketones

Overview

The synthesis of polyfluorinated diketoesters and tetraketones through condensation reactions of perfluorinated dicarboxylic acid esters with alkyl ketones was investigated. Dialkyl esters of perfluoroadipic and perfluoropimelic acids served as starting materials, with particular emphasis on the reactivity of dimethyl perfluorododecanedioate as a substrate for tetraketone formation.

Methods and approach

Diketoesters were synthesized via direct reaction of dialkyl esters of perfluoroadipic and perfluoropimelic acids with alkyl ketones. The tetraketone synthesis utilized dimethyl perfluorododecanedioate as the ester substrate. Reaction conditions were systematically varied, including solvent selection, with tetrahydrofuran evaluated as an alternative medium. Computational investigations employing non-empirical MP2/6-31G* quantum chemical calculations were conducted to model possible reaction intermediates and mechanistic pathways.

Key Findings

The reaction of perfluorinated dicarboxylic acid esters with alkyl ketones yielded diketoesters and tetraketones as products. Tetrahydrofuran was identified as a superior reaction medium, demonstrating increased product yields compared to alternative solvents. Computational calculations at the MP2/6-31G* level provided theoretical support for proposed reaction mechanism stages, clarifying the transformations occurring during the condensation process.

Implications

The identified conditions and mechanistic framework establish parameters for optimizing the synthesis of polyfluorinated keto compounds, a class of materials with potential applications in fluorine chemistry. The demonstration that solvent choice significantly impacts reaction efficiency indicates that further optimization of reaction conditions may yield additional improvements in synthetic accessibility. Computational validation of mechanistic pathways provides a foundation for predicting reactivity patterns in related perfluorinated substrates.