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Страница 86.

Например:
When 3-nitropurin or 2-hydroxy-3-nitroanthra-l,4,9,10—di-quinone is oxidised in methanol with lead dioxide or potassium permanganate 2-hydroxy-3-nitroacetyl-l,4-naphthaquinone (III) is formed directly.
After being stored overnight, the solutions were neutralized with acetic acid and evaporated. The products were only partly soluble in water, so the deacetylation was repeated to give material completely soluble in water. This was treated with Biodeminrolit resin and evaporated to a syrup.
(a) 3-Nitroalizarin. When 3-nitroalizarin was oxidised in methanol with lead dioxide the first relatively stable product was a methyl ether (I) of 3-nitropurpurin, which on hydrolysis with aqueous hydrobromic acid was converted into 3-nitropurpurin (I). Solvent was removed and the polymer was precipitated with 1 : 1 ether-cyc-lohexane (3 с. с. ), then dissolved in water and neutralised with tri-butylamme. The trisaccharide (10 mg. ) was reduced with sodium borohydride (20 mg. ) for 24 hr. When it was hydrolysed with 1,5 N — sulphuric acid for 6 hr. the glucose liberated amounted to 65% of that from an equivalent weight of unreduced trisaccharide. The acetates were extracted with chloroform (3 X 100 ml), and the combined extracts were washed with sodium hydrogen carbonate solution and water and then dried (Na2S04). In a trial experiment the dextran was hydrolysed with dilute sulphuric acid to degrees of conversion into glucose ranging from 20 to 51 %.
Optical spectra were measured with a Gary recording spectrophotometer. The column was eluted with water to remove glucose.
§ 139. Встречается также употребление предлогов with и by в тождественных контекстах , что, по-видимому, указывает на отсутствие сознательной дифференциации между орудием действия и непосредственным деятелем.
Например:
The acid polysaccharide (3g. ) was hydrolysed by N-sulphuric acid (50 ml. ) at 100° for 4 hr. Since chromatography showed several oligosaccharides, both neutral and acidic, the mixture was
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rehydrolysed with N-sulphuric acid (30 ml. ) at 100° for 2 hr. In a similar reaction but with decomposition by water and ice, sulphur (0,7 g. ) was obtained from the ethereal and thiolbenzoic acid from the aqueous layer. In a similar reaction decomposition with water afforded an unidentified oil from the ethereal layer and benzoic acid from the aqueous layer.
Thus 1 mol. of dibenzoyl disulphide with 3 mols. of phenylmag-nesium bromide or phenyl-lithium afforded triphenylrnethyl thi-olbenzoate after decomposition by acid. Decomposition with ammonium chloride in case of the magnesium compounds and with water in case of lithium compounds gave, as expected, the triarylmethanols.
2-Phenylethanol has been found to be oxidised by ammonium metavandate to benzaldehyde, benzoic acid, and formic acid under conditions in which (a) dehydration to styrene did not occur and (b) phenylacetic acid was not oxidised, whilst (c) benzyl alcohol was rapidly oxidised. This olefin is only slowly oxidisedby vanadium (V), a:id it cannot be the immediate precursor. Mild oxidation of either y-oxo-y-2-xanthenylbutyric acid (I) or its methyl ester by potassium permanganate in aqueous acetone yielded y-oxo-y-2-xanthonylbutyric acid (II; R=H) or its methyl ester respectively.
Oxidation of the sugar with periodate gave 0,06 mol. of formaldehyde. Reduction of the sugar with potassium borohydride followed by oxidation with periodate gave 0. 87 mol. of formaldehyde.
It may be emphasised that in dioxan solution no significant phosphorylation of 5'-hydroxyl groups by diphenyl phosphorochlo-ridate occurred under the conditions employed. The present paper deals with the chemical oxidation of 3-nitro-alizarin and -purpurin by lead dioxide and potassium permanganate in methanol containing some acetic acid; in the following paper we compare the course of this oxidation with the photochemical degradation.

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