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The original reaction was a mixture of the reagents phenol, chloroform, and acetone in the presence of a sodium hydroxide solution. [2] Prior to Bargellini's research, the product attributed to this multi-component reaction (MCR) had been described as a phenol derivative in chemistry texts at the time.
The mechanism of the Reimer-Tiemann reaction. Chloroform (1) is deprotonated by a strong base (normally hydroxide) to form the chloroform carbanion (2) which will quickly alpha-eliminate to give dichlorocarbene (3); this is the principal reactive species. The hydroxide will also deprotonate the phenol (4) to give a negatively charged phenoxide ...
Phenol is often used in combination with chloroform. [4] Adding an equal volume of chloroform and phenol ensures a distinct separation between the aqueous and organic phases. Chloroform and phenol are miscible and create a denser solution than phenol alone, aiding the separation of the organic and aqueous layers. This addition of chloroform is ...
At the end of 1875, Karl Reimer independently developed a new synthetic route to aromatic aldehydes by reacting aqueous phenolate solutions with chloroform (Reimer's reaction). Compared to Ferdinand Tiemann, [4] [5] [6] Karl Reimer decided not to carry out much scientific research into his own reaction's proofs and uses. [7]
Typically these reactions would be conducted in the presence of a base which serves to absorb the HCl. Alkyl chloroformate esters degrate to give the alkyl chloride, with retention of configuration: ROC(O)Cl ' → RCl + CO 2. The reaction is proposed to proceed via a substitution nucleophilic internal mechanism. [3]
Chloroform: Chloroform is stabilized with small quantities of amylene or ethanol, because exposure of pure chloroform to oxygen and ultraviolet light produces phosgene gas. Some chloroform solutions come as pre-made a 96% chloroform, 4% isoamyl alcohol mixture that can be mixed with an equal volume of phenol to obtain the 25:24:1 solution.
Aqueous samples, lysed cells, or homogenised tissue are mixed with equal volumes of a phenol:chloroform mixture. This mixture is then centrifuged. Because the phenol:chloroform mixture is immiscible with water, the centrifuge will cause two distinct phases to form: an upper aqueous phase, and a lower organic phase.
A chlorophenol is any organochloride of phenol that contains one or more covalently bonded chlorine atoms. There are five basic types of chlorophenols (mono- to pentachlorophenol) and 19 different chlorophenols in total when positional isomerism is taken into account. Chlorophenols are produced by electrophilic halogenation of phenol with ...