OXIDATION OF ALCOHOLS BY IODINE
747
methylene chloride–NaHCO3 aqueous solution (pH 8.6)
was as follows.
ary alcohols using the mediator system of a nitroxyl radi-
cal of the 2,2,6,6-tetramethylpiperidine series–potassium
iodide results in the formation of aldehydes and ketones,
respectively, with a high yield of the compounds.
An alcohol, 0.05 mol, dissolved in 30 ml of methy-
lene chloride, NaHCO3, 5 g (0.06 mol), and KI, 2 g
(0.01 mol), dissolved in 70 ml of distilled water were
poured in a 150 ml diaphragmless electrolyzer supplied
with a mechanical stirrer, a water jacket, and two plati-
num electrodes (anode 20 cm2, cathode 15 cm2). Then
0.005 mol of the nitroxyl radical was added. Electrolysis
conditions: temperature 20–25°, current strength of 0.5A
(anode current density 0.025Acm–2), maximal voltage on
the electrolyzer 10 V, and intensive stirring. The synthesis
was finished after passing 4 Ф mol–1 of electricity. After
electrolysis termination the organic layer was separated.
The aqueous layer was extracted with methylene chloride
(2 × 50 ml), organic extract were merged and dried by
anhydrous sodium sulfate. According to TLC, reaction
mixtures contained two substances, an initial alcohol and
an oxidation product. Contents of alcohol and aldehyde
(ketone) were determined by the GLC method.
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To isolate an aldehyde (ketone), the solvent was
removed, and the residual was distilled in vacuo: cyclo-
hexanone at 60–62°C (10 mm Hg); phenylacetic aldehyde
at 78–79°C (10 mm Hg), and benzaldehyde at 62–63°C
(10 mm Hg). The yield of the corresponding carbonyl
compound was 75–85% (of isolated product).
6. Golubev, V.A., Kozlov, Yu.N., Petrov, A.N., and Purmal’,
A.P., Nitroksil’nye radikaly: Sintez, khimiya, prilozheniya
(Nitroxyl Radicals: Synthesis, Chemistry, Applications),
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CONCLUSIONS
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Iminoxyl Radicals), Moscow: Khimiya, 1970.
The electrochemical oxidation of primary and second-
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