Thallium nitrate, reaction with

Alkyl aryl ketones can be converted to arylacetic acid derivatives in an entirely different manner. The reaction consists of treatment of the substrate with silver nitrate and I2 or Br2, ° or with thallium nitrate, MeOH, and trimethyl orthoformate adsorbed on Montmorillonite K-10 clay, an acidic clay. ... 

The potassium derivatives obtained from the reaction mixture are typically not isolated in pure form, and the crude products are often converted directly to the thallium complexes by metathesis with either thallium nitrate or thallium acetate [Eqs. (1) and (2)]. 

Methyl arylacetates.2 Aryl methyl ketones are converted into methyl arylacetates by reaction with BF3 etherate and lead tetraacetate in benzene at room temperature (equation I). Thallium(lll) nitrate (4, 496) has also been used for this modified Willgerodt-Kindler reaction. 

Although the isomeric chromenes (48) and (49) obtained from the isoflavanone (47) and 3-chloro-3-methylbut-l-yne could not be separated by chromatography, a chemical separation was achieved. Ring contraction of the 7-methoxy isomer (49) to the benzofuran (50) occurred on reaction with thallium(III) nitrate in methanol the 5-methoxy compound was unaffected. The resulting mixture was readily separated <8iG2li). 

Evidence has been presented that 2-hydroxychalcones are also transformed into flavones on reaction with thallium(III) nitrate (equation 16) (78TL3359). Such a method would be complementary to the isoflavone synthesis if it proves to be of general applicability. 

Flavylium salts are oxidized to flavones on treatment with thallium(III) nitrate in methanol. The reaction is considered to involve initial attack at C-2 by methanol. The resulting chromene (484) undergoes reaction with the thallium salt at C-3 and nucleophilic attack at C-4 by methanol to give an unstable adduct (485), which decomposes to the flavone... 

The action of n-butyllithium in THF at low temperature leads to the anion. After reaction with an electrophilic compound, e hydrolysis can generally be carried out in polar solvents (acetone, alcohols, acetonitrile) in the presence of mercury(II) chloride or oxide and water.In other cases, NBS, - chloramine T, cerium(IV) ammonium nitrate, n-tributyltin hydride, trialkyloxonium tetrafluorobor-ate, thallium nitrate or photochemistry can be used. Desulfurization by Raney nickel gives hydro-carbons. ... 

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