Gattermann condensation

The Gattermann condensation reaction and its modifications, the Vilsmeier reaction as well as the use of modified Friedel-Crafts and Grignard reactions, offer useful methods for the laboratory synthesis of aromatic and heterocyclic aldehydes. 

Gabriel condensation, 124-126 Ing-Manske modification, 124-126 Gattermann condensation, 50 Goldberg reaction, 93 Grignard coupling, 14-15,17 Grignatd method, 54-56 Grignard reaction, 31,50, 59,94,176,187, 246-248... 

Hoesch synthesis A variation of the Gattermann synthesis of hydroxy-aldehydes, this reaction has been widely applied to the synthesis of anthocyanidins. It consists of the condensation of polyhydric phenols with nitriles by the action of hydrochloric acid (with or without ZnCl2 as a catalyst). This gives an iminehydrochloride which on hydrolysis with water gives the hydroxy-ketone. 

By the condensation of a nitrile with a phenol or phenol ether in the presence of zinc chloride and hydrogen chloride a hydroxyaryl- or alkoxyaryl-ketone is produced. The procedure is termed the Hoesch reaction and is clearly an extension of the Gattermann aldehyde reaction (Section IV,121). The reaction gives the best results with polyhydric phenols and their ethers with simple monohydric phenols the imino ester hydrochloride is frequently the sole product for example ... 

The fundamental object of his researches differs from that of Gattermann, in that Lob undertakes to establish the separate phases of the reduction of the nitro-group. This he accomplishes by the addition of formaldehyde to the electrolyte under varying conditions, and as a result the intermediate products, at the moment of their formation, combine with formaldehyde, producing condensation compounds which do not undergo further decomposition. By regulating the potential or density of the current the reaction can at... 

O. R. XVIII-I, M. J. Jorgenson, Preparation of Ketones from the Reaction of Organo-lithium Reagents with Carboxylic Acids XVI, A. J. Nielsen and W. J. Houlihan, The Aldol Condensation IV-5, W. S. Ide and J. S. Buck, The Synthesis of Benzoins II-3, T. A. Geissman, The Cannizzaro Reaction V-6, N. N. Crounse, The Gattermann-Koch Reaction I-10, F. f. 3licke, The Mannich Reaction. ... 

Gattermann has obtained direct proof of the intermediate formation of phenyl-hydroxylamine by adding benzaldehyde to the solution at the beginning of the electrolysis. He was thus able to isolate a condensation product of phenyl-hydroxylamine with benzaldehyde. In this way he obtained benzylidene-phenyl-hydroxylamine,... 

Gattermann Aldehyde Synthesis Gattermann Reaction Gattermann-Koch Reaction Glaser Coupling Glycidic Ester Condensation... 

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