Separation of Aldehydes and Reactive Ketones from Mixtures Using a Bisulfite Extraction Protocol

Abstract

The purification of organic compounds is an essential component of routine synthetic operations. The ability to remove contaminants into an aqueous layer by generating a charged structure provides an opportunity to use extraction as a simple purification technique. By combining the use of a miscible organic solvent with saturated sodium bisulfite, aldehydes and reactive ketones can be successfully transformed into charged bisulfite adducts that can then be separated from other organic components of a mixture by the introduction of an immiscible organic layer. Here, we describe a simple protocol for the removal of aldehydes, including sterically-hindered neopentyl aldehydes and some ketones, from chemical mixtures. Ketones can be separated if they are sterically unhindered cyclic or methyl ketones. For aliphatic aldehydes and ketones, dimethylformamide is used as the miscible solvent to improve removal rates. The bisulfite addition reaction can be reversed by basification of the aqueous layer, allowing for the re-isolation of the reactive carbonyl component of a mixture.

From Waste to Value—Direct Utilization of α-Angelica Lactone as a Nonconventional Irreversible Acylating Agent in a Chromatography-Free Lipase-Catalyzed KR Approach toward sec-Alcohols

“…To testify our hypothesis, we started our investigations on the separation of an equimolar mixture of model racemic alcohol–levulinate pair: rac - 1a and rac - 2a (Table ). During screening, we have utilized various conditions adapted in analogy to literature protocols reported by Furigay et al, Boucher et al, and Silverman et al Unfortunately, all attempts failed regardless of the method used (for details, see the Supporting Information). In the best scenario, when a 1:1 mixture of rac - 1a and rac - 2a was dissolved in DMF and then washed sequentially with saturated aqueous sodium bisulfate used in a 2:5 v/v ratio, alcohol rac - 2a could be recovered after a convenient workup procedure in 29 and 97% purity according to GC, whereas levulinate rac - 1a in 34% recovery and 84% purity according to GC (Table , entry 3).…”

Application of Zr-Cluster-Based MOFs for the Adsorptive Removal of Aliphatic Aldehydes (C1 to C5) from an Industrial Solvent

“…The purification of organic solvents is an integral part of routine chemical synthesis processes in various industries. , In this regard, the ability to effectively purify a given organic solvent by separating out prevalent impurities (e.g., particular chemical species) is an important task for analytical chemists, organic chemists, chemical engineers, and industrial/environmental scientists. − Carbonyl compounds (CCs) such as aldehydes are a class of chemicals required in the synthesis of various products (resins, polymers, plasticizers, carboxylic acids, detergents, dyes, pharmaceuticals, and other niche chemicals). Consequently, the separation and recovery of aldehydes from industrial solvents is essential because a certain portion of CCs can remain in the spent organic solvent upon the completion of the desired chemical synthesis process. , …”

“…At present, liquid–liquid extraction (LLE) is one of the process operations most commonly used to remove CCs from industrial solvents . A well-known LLE approach involves the reaction of bisulfites with CCs to yield charged bisulfite adducts as the end product, which facilitates the removal of dissolved CCs. , However, this LLE technique suffers from technical shortcomings such as a need for large amounts of solvents, low quantitative recovery, and incomplete separation of phases, which restrict its practical application. , …”

“…Relatively little is known about the adsorptive potential of Zr-based MOFs in the presence of multiple targets (i.e., heavier (C 2 –C 5 ) aldehyde species than FA (C 1 )) under competitive sorption conditions. Given that lighter and heavier CCs frequently coexist in industrial solvents (e.g., methanol), we decided to analyze the performances of Zr-MOF sorbents (U6 and U6N) toward CCs as both single- and multicomponent targets. , …”

“…Consequently, the separation and recovery of aldehydes from industrial solvents is essential because a certain portion of CCs can remain in the spent organic solvent upon the completion of the desired chemical synthesis process. 6,7 CCs are commonly recognized as critical environmental pollutants because they are mutagenic and carcinogenic. 8,9 The toxicity of aldehydes originates from their high propensity to form complexes with nucleophilic sites in biological systems (e.g., amino acid side chains such as lysyl groups and cysteinyl thiol) via Cannizzaro-or Mannich-type reactions.…”