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Morse's cited article describes the synthesis of paracetamol from 4-aminophenol and acetic acid. [6] Phenacetin may be synthesized as an example of the Williamson ether synthesis: ethyl iodide, paracetamol, and anhydrous potassium carbonate are heated in 2-butanone to give the crude product, which is recrystallized from water. [7]
The Williamson ether synthesis is an organic reaction, forming an ether from an organohalide and a deprotonated alcohol . This reaction was developed by Alexander Williamson in 1850. [ 2 ] Typically it involves the reaction of an alkoxide ion with a primary alkyl halide via an S N 2 reaction .
Alexander Williamson. Williamson is credited for his research on the formation of unsymmetrical ethers by the interaction of an alkoxide with a haloalkane, known as the Williamson ether synthesis. He regarded ethers and alcohols as substances analogous to and built up on the same type as water, and he further introduced the water-type as a ...
Bis-aryl ethers (such as diphenyl ether) cannot be synthesized through the Williamson ether synthesis, however, as aryl halides cannot undergo nucleophilic substitution. As such, an Ullmann condensation can be employed: an aryl halide is able to react with phenol (or its derivatives) to form a bis-aryl ether in the presence of a copper-based ...
18-Crown-6 can be synthesized by the Williamson ether synthesis using potassium ion as the template cation. Structure of nickel-aquo nitrate complex of the ligand derived from the templated trimerization of 2-aminobenzaldehyde. [5] The phosphorus analogue of an aza crown can be prepared by a template reaction. [6]
Sodium phenoxide reacts with alkylating agents to afford alkyl phenyl ethers: [2] NaOC 6 H 5 + RBr → ROC 6 H 5 + NaBr. The conversion is an extension of the Williamson ether synthesis. With acylating agents, one obtains phenyl esters: [citation needed] NaOC 6 H 5 + RC(O)Cl → RCO 2 C 6 H 5 + NaCl
The Dieckmann method is practical only for 5- to 8-membered rings (with modest yields for 7- and 8-membered). The Thorpe method is more easily modified via high dilution (e.g., 0.001 M in benzene/ether) to enable the synthesis of large rings, but 4-membered and 9- to 13-membered rings are still not accessible.
Synthesis from the latter chemical is accomplished through a condensation reaction with glyoxylic acid followed by cleaving the resulting α-hydroxy acid with an oxidizing agent. [ 3 ] [ 4 ] [ 5 ] Synthesis from catechol requires an additional step, Williamson ether synthesis using dichloromethane .