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In organic chemistry, an azo coupling is an reaction between a diazonium compound (R−N≡N +) and another aromatic compound that produces an azo compound (R−N=N−R’).In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile, and the activated carbon (usually from an arene, which is called coupling agent), serves as a nucleophile.
Notice that the coupling occurs adjacent to the hydroxy group. 3-Hydroxy-2-naphthoic acid is a precursor to many anilides, such as Naphthol AS, which are reactive toward diazonium salts to give deeply colored azo compounds. Azo coupling of 3-hydroxy-2-naphthoic acid gives many dyes as well. Heating 3-hydroxy-2-naphthoic acid in ammonia give 3 ...
The following other wikis use this file: Usage on fi.wikipedia.org Diatsoniumsuolat; Atsokytkentä; Usage on hu.wikipedia.org Diazóniumvegyületek
Alizarine Yellow R is a yellow colored azo dye made by the diazo coupling reaction. It is usually commercially available as a sodium salt. It is usually commercially available as a sodium salt. In its pure form, it is a rust-colored solid. [ 2 ]
Azobenzene is a photoswitchable chemical compound composed of two phenyl rings linked by a N=N double bond.It is the simplest example of an aryl azo compound.The term 'azobenzene' or simply 'azo' is often used to refer to a wide class of similar compounds.
Couplage azo; Usage on hu.wikipedia.org Diazóniumvegyületek; Usage on id.wikipedia.org Senyawa diazonium; Usage on it.wikipedia.org Sale di diazonio; Reazione di copulazione; Utente:Grasso Luigi/sanbox1/sale di diazonio; Usage on ja.wikipedia.org アゾカップリング; Usage on ro.wikipedia.org Sare de diazoniu; Cuplare azoică; Colorant azoic
The reaction mechanism of the Mitsunobu reaction is fairly complex. The identity of intermediates and the roles they play has been the subject of debate. Initially, the triphenyl phosphine (2) makes a nucleophilic attack upon diethyl azodicarboxylate (1) producing a betaine intermediate 3, which deprotonates the carboxylic acid (4) to form the ion pair 5.
This method can also be used with primary diazoalkanes, to produce secondary α-diazo ketones. However, there are many limitations. Primary diazoalkanes undergo azo coupling to form azines; thus the reaction conditions must be altered such that acid chloride is added to a solution of diazoalkane and triethylamine at low temperature.