Search results
Results from the WOW.Com Content Network
Bogdanovic and Bolte identified the nature and mode of action of the active species in some classical McMurry systems, [5] and an overview of proposed reaction mechanisms has been published. [3] It is of note that titanium dioxide is not generally a product of the coupling reaction.
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.
Retention increases as the fraction of the polar solvent (water) in the mobile phase is higher. Normal phase chromatography retains molecules via an adsorptive mechanism, and is used for the analysis of solutes readily soluble in organic solvents. Separation is achieved based on the polarity differences among functional groups such as amines ...
1,3-Diisopropylbenzene is produced via transalkylation, a special form of Friedel–Crafts alkylation. It also allows alkyl chains to be added reversibly as protecting groups. This approach is used industrially in the synthesis of 4,4'-biphenol via the oxidative coupling and subsequent dealkylation of 2,6-di-tert-butylphenol. [11] [12]
Ammonium sulfate is an inorganic salt with a high solubility that disassociates into ammonium (NH + 4) and sulfate (SO 2− 4) in aqueous solutions. [1] Ammonium sulfate is especially useful as a precipitant because it is highly soluble, stabilizes protein structure, has a relatively low density, is readily available, and is relatively inexpensive.
The mechanism of reductions of aldehydes and ketones by samarium(II) iodide is based primarily on mechanisms elucidated for similar one-electron reducing agents. [12] Upon single-electron transfer, a ketyl dimer iv forms. In the absence of protic solvent, this dimer collapses to form 1,2-diols.
The resulting product, diethyl 3,5-dimethylpyrrole-2,4-dicarboxylate, has been called Knorr's Pyrrole ever since. In the Scheme above, R 2 = COOEt, and R 1 = R 3 = Me represent this original reaction. Knorr's pyrrole can be derivatized in a number of useful manners. One equivalent of sodium hydroxide will saponify the 2-ester selectively.