Gattermann-Koch synthesis

The Gattermann-Koch synthesis is suitable for the preparation of simple aromatic aldehydes from ben2ene and its substituted derivatives, as well as from polycychc aromatics. The para isomers are produced preferentially. Aromatics with meta-directing substituents cannot be formylated (108). 

Toniolo, L., Graziani, M. Metals in organic syntheses. V. The Gattermann-Koch synthesis of aromatic aldehydes promoted by CuCI(PPh3) (n = 0,1 or 3). Is the cuprous complex necessary in the synthesis of tolualdehyde J. Organomet. Chem. 1980,194, 221-228. 

The Gattermann-Koch synthesis may be expressed by the following equation ... 

In the preparation of this new edition advantage has been taken of the opportunity offered to correct a number of errors in the first edition, and to make the text a reproduction of the fourth German edition of Professor Gattermann s book. In many cases the laboratory directions have been improved, a number of new illustrations have been added, and the Special Part now includes methods for the preparation of glycol, di-methylcyclohexenone, s-xylenol, phenylhydroxylamine, nitroso-benzene, p-tolyl aldehyde (Gattermann-Koch synthesis), salicylic aldehyde (Reimer and Tiemann s oxyaldehyde synthesis), cuprous chloride, the decomposition of inactive mandelic acid into its active constituents, and a zinc dust determination. The preparations of acetylene and acetylene tetrabromide have been omitted. 

Gabriel phthalimide synthesis, 12, 10 Gattermann-Koch synthesis of an aldehyde, 12, 80 Gelatine, 12, 4... 

This is known as the Gattermann-Koch synthesis. It is used industrially in special cases but is less suitable for laboratory work because it is preparatively inconvenient and tedious and must often be conducted under pressure. Its use is mainly restricted to treatment of alkylbenzenes. 

The Gattermann-Koch synthesis fails with phenols and aryl ethers. However, Gattermann showed1061,589 that good results were obtained if such compounds were treated with hydrogen chloride and hydrogen cyanide in the presence of zinc chloride the aldimine hydrochloride is first formed and gives the aldehyde on hydrolysis ... 

The Gattermann-Koch synthesis of aromatic aldehydes involves a Friedel-Crafts formylation by CICHO in the presence of aluminum chloride and CuCl catalysts. s.n xhe reaction proceeds without Cu, but at much higher pressures. s... 

Gattermann-Koch synthesis s. 13,183 One step isoflavone synthesis... 

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