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). 

The octylphenol condensate is used as an additive to lubricating oils and surface-active agents. Other uses of dimer are amination to octylamine and octyldiphenylamine, used in mbber processing hydroformylation to nonyl alcohol for phthalate production and carboxylation via Koch synthesis to yield acids in formulating paint driers (see Drying). 

An overall kinetic study on the Koch synthesis of succinic acid from acrylic acid and carbon monoxide in SO3—HaS04 has recently been reported (Sngita et. al., 1970). 

As mentioned in the Introduction, rearrangements of the intermediate alkyl cation in the Koch synthesis may compete with the carbonylation. Under the kinetically controlled conditions prevailing in the Koch synthesis of carboxylic acids, the rearrangements occur only from a less stable to a more stable carbonium ion, e.g. from a secondary to a tertiary ion. The reverse rearrangements—from a more stable to a less stable... 

First, the rates of carbonylation of secondary and tertiary alkyl carbonium ions can now be compared quantitatively with the known rates of competing intramolecular rearrangements of these ions. The product distribution in the Koch synthesis of carboxylic acids depends, amongst other things, on these relative rates. 

Gatterman-Koch synthesis org chem A synthesis of aldehydes aldehydes form when an aromatic hydrocarbon is heated in the presence of hydrogen chloride, certain metallic chloride catalysts, and either carbon monoxide or hydrogen cyanide. gad-3r-man kok, sin-th3-s3s ... 

Show how you would use the Friedel-Crafts acylation, Clemmensen reduction, and/or Gatterman-Koch synthesis to prepare the following compounds ... 

The Gatterman-Koch synthesis is a variant of the Friedel-Crafts acylation in which carbon monoxide and HC1 generate an intermediate that reacts like formyl chloride. Like Friedel-Crafts reactions, the Gatterman-Koch formylation succeeds only with benzene and activated benzene derivatives. 

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... 

For example, industrially, pivalic acid is prepared from CO and butene isomers at 80°C and 20-100 atm (Koch synthesis). ... 

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