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In this example the organic layer is the product, which is a liquid at room temperature. The bottom aqueous layer is removed with a pipette and discarded. The top layer is transferred to an Erlenmeyer flask where it is treated with anhydrous sodium sulfate to remove any remaining water.
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]
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
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]
Aqueous biphasic systems (ABS) or aqueous two-phase systems (ATPS) are clean alternatives for traditional organic-water solvent extraction systems.. ABS are formed when either two polymers, one polymer and one kosmotropic salt, or two salts (one chaotropic salt and the other a kosmotropic salt) are mixed at appropriate concentrations or at a particular temperature.
An example of the E1cB reaction mechanism in the degradation of a hemiketal under basic conditions. The E1cB elimination reaction is a type of elimination reaction which occurs under basic conditions, where the hydrogen to be removed is relatively acidic, while the leaving group (such as -OH or -OR) is a relatively poor one.
Upon workup by acidic hydrolysis the primary amine is liberated as the amine salt. [11] Alternatively the workup may be via the Ing–Manske procedure, involving reaction with hydrazine. This method produces a precipitate of phthalhydrazide (C 6 H 4 (CO) 2 N 2 H 2) along with the primary amine: C 6 H 4 (CO) 2 NR + N 2 H 4 → C 6 H 4 (CO) 2 N 2 ...