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The Buchner ring expansion reaction was first used in 1885 by Eduard Buchner and Theodor Curtius [1] [2] who prepared a carbene from ethyl diazoacetate for addition to benzene using both thermal and photochemical pathways in the synthesis of cycloheptatriene derivatives. The resulting product was a mixture of four isomeric carboxylic acids ...
Upon heating, 2,4,6-trinitrobenzoic acid undergoes decarboxylation to give 1,3,5-trinitrobenzene. [4] Reduction with tin gives 2,4,6-triaminobenzenoic acid, a precursor to phloroglucinol (1,3,5-trihydroxybenzene).
Here decarbonylation accompanies the preparation of cyclopentadienyliron dicarbonyl dimer: 2 Fe(CO) 5 + C 10 H 12 → (η 5 −C 5 H 5) 2 Fe 2 (CO) 4 + 6 CO + H 2. Decarbonylation can be induced photochemically as well as using reagents such as trimethylamine N-oxide: Me 3 NO + L + Fe(CO) 5 → Me 3 N + CO 2 + LFe(CO) 4
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO 2). Usually, decarboxylation refers to a reaction of carboxylic acids , removing a carbon atom from a carbon chain.
Benzoic acid is cheap and readily available, so the laboratory synthesis of benzoic acid is mainly practiced for its pedagogical value. It is a common undergraduate preparation. Benzoic acid can be purified by recrystallization from water because of its high solubility in hot water and poor solubility in cold water. The avoidance of organic ...
The reaction is named after Cläre Hunsdiecker and her husband Heinz Hunsdiecker, whose work in the 1930s [5] [6] developed it into a general method. [1]The reaction was first demonstrated by Alexander Borodin in 1861 in his reports of the preparation of methyl bromide (CH 3 Br) from silver acetate (CH 3 CO 2 Ag).
The reaction product is a derivative of benzene. Scheme 1. Bergman cyclization. The reaction proceeds by a thermal reaction or pyrolysis (above 200 °C) forming a short-lived and very reactive para-benzyne biradical species. It will react with any hydrogen donor such as 1,4-cyclohexadiene which converts to benzene.
Sodium hypochlorite, [4] lead tetraacetate, [5] N-bromosuccinimide, and (bis(trifluoroacetoxy)iodo)benzene [6] can effect a Hofmann rearrangement. The intermediate isocyanate can be trapped with various nucleophiles to form stable carbamates or other products rather than undergoing decarboxylation.