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The product is isolated from the mixture by the following work-up: [3] Synthesis of 4-methylcyclohexene with work-up step in red. A concentrated solution of sodium chloride in water, known as a brine solution, is added to the mixture and the layers are allowed to separate. The brine is used to remove any acid or water from the organic layer.
Acid–base extraction is a subclass of liquid–liquid extractions and involves the separation of chemical species from other acidic or basic compounds. [1] It is typically performed during the work-up step following a chemical synthesis to purify crude compounds [2] and results in the product being largely free of acidic or basic impurities.
The resulting hydroquinone is poorly soluble in typical reaction solvents (dioxane, benzene, alkanes), which facilitates workup. Solutions of DDQ in benzene are red, due to the formation of a charge-transfer complex. [9]
Phase 1 is typically an organic solvent and 2 an aqueous phase. Laboratory-scale liquid-liquid extraction. Photograph of a separatory funnel in a laboratory scale extraction of 2 immiscible liquids: liquids are a diethyl ether upper phase, and a lower aqueous phase. Schematic representation of a Soxhlet extractor:
For example, nonylmagnesium bromide reacts with methyl p-chlorobenzoate to give p-nonylbenzoic acid, in the presence of Tris(acetylacetonato)iron(III) (Fe(acac) 3), after workup with NaOH to hydrolyze the ester, shown as follows. Without the Fe(acac) 3, the Grignard reagent would attack the ester group over the aryl halide. [21]
It is a common observation that when oil and water are poured into the same container, they separate into two phases or layers, because they are immiscible.In general, aqueous (or water-based) solutions, being polar, are immiscible with non-polar organic solvents (cooking oil, chloroform, toluene, hexane etc.) and form a two-phase system.
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base.It can be used to determine pH via titration.Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory.
The mechanism of the reaction involves two steps. The first step is a nucleophilic addition to the nitrile with the aid of a polarizing Lewis acid, forming an imine, which is later hydrolyzed during the aqueous workup to yield the final aryl ketone. Hoesch reaction mechanism