Oxidation by sodium dichromate

A hydroxyl group in the neighborhood of fluoroalkyl is oxidized by sodium dichromate to yield a ketone [481 (equation 44)... 

CHPh2, R" = H), which was oxidized by sodium dichromate-acetic acid to V-(diphenylmethyl)isatin.510... 

Toluene and its substituted derivatives are oxidized by sodium dichromate or chromyl chloride mainly into the corresponding benzoic acids or benzaldehydes in good yields.270 No or very little ring hydroxylation is observed. 

Tertiary alcohols aren t oxidized by sodium dichromate. 

In acenaphthene, both methylene groups are oxidized by sodium dichromate to give acenaphthenequinone (equation 180) [625]. 

According to a recent paper 250 cf. 251),. V,0-diacetylsolasodine (227) was oxidized by sodium dichromate in aqueous acetic acid to the diketone 228, which could be transformed by Grignard addition and treatment with HCl into the 16-alkyl-substituted furostadiene derivative 229. 

Removal of the ketal protecting groups, followed by oxidation with sodium dichromate ia acetic acid gave... 

The starting materials of the aldehyde method may be sulfonated. For example. Cl Acid Blue 9 [2650-18-2] Cl Food Blue 2 (Cl 42090), is manufactured by condensing a-(A/-ethylanilino)-y -toluenesulfonic acid with o-sulfobenzaldehyde. The leuco base is oxidized with sodium dichromate to the dye, which is usually isolated as the ammonium salt. In this case, the removal of the excess amine is not necessary. However, this color caimot be used in the food sector because separation of the chromium compounds from the dye is difficult. An alternative method which gives food-grade Cl Acid Blue 9 (14) and dispenses with the use of sodium dichromate employs oxidative electrolysis of the leuco base (49). 

Terephthalic acid has been obtained from a great many /)-disubstituted derivatives of benzene or cyclohexane by oxidation with permanganate, chromic acid, or nitric acid. The following routes appear to have preparative value from />-toluic acid, />-methylacetophenone,2 or dihydro-/)-tolualdehyde by oxidation with permanganate from f>-cymene by oxidation with sodium dichromate and sulfuric acid from />-dibromobenzene or from /i-chloro- or -bromobenzoic acid by heating at 250° with potassium and cuprous cyanides and from />-dibromo-benzene, butyllithium, and carbon dioxide. ... 

The synthesis of fluoroalkyl and chloroalkyl fluoromethyl ketones is achieved by oxidation of the corresponding alcohols by sodium dichromate and sulfunc acid in methylene chlonde in the presence of a phase transfer catalyst [49] (equation 45)... 

Write the structural formula for the product of (a) the reaction of glycerol (1,2,3-trihydroxypropane) with stearic acid, CH5(CH2)16COOH, to produce a saturated fat (b) the oxidation of 4-hydroxybenzyl alcohol by sodium dichromate in an acidic organic solvent. 

Acridine is readily oxidized to acridone by sodium dichromate and acetic acid. Pyridin-2-one and nicotinic acid have been found to undergo oxidation to oxalic add on treatment with Fenton s reagent (69CHE563). 

Oxidation—Continued by fuming nitric acid, 23, 3 by hydrogen peroxide, 20, 70 by nitric acid, 27, 84 by potassium chlorate, 23, 6 by potassium permanganate, 20, 79 by sodium dichromate and sulfuric acid, 25, 81... 

A rearrangement of strychnine-IV-oxide catalyzed by sodium dichromate in boiling water gives almost quantitative conversion into two products in equal amounts one of these is pseudostrychnine (XXV) and the other is 18-oxostrychnine. It is interesting that no product corresponding to oxidation of C-20 seems to be formed (143a, 127). 

Compound 87 (R = r-Bu, R = Ph, R = H) has been prepared by addition of tert-butylmagnesium chloride to 1-phenylphthalide (102) and subsequent dehydration with p-toluenesulfonic acid. It is described as a yellow oil with brilliant fluorescence under UV light, which on oxidation with sodium dichromate yields diketone 103. Compound 87 (R = /-Bu, R = Ph, R = H) with dimethyl acetylenedicarboxylategives 104(mp 128-129 C, 80%) on reduction 105 is obtained 105 is also accessible from 87 (R = <-Bu, R = Ph, R = H) and dimethyl maleate (mp 151-152°C, endo) a maleic anhydride adduct has also been described (mp 147.5-148°C, 83%). Diels-Alder adducts have been also prepared from the benzo[c]furan precursors 106 (R = CHjPh, R = H, Ph) in the presence of catalytic amounts of acid 107 (mp 141-142.5X, 70%) and 108 (mp 140-141.5°C, 49%) were obtained, which on catalytic hydrogenation (Pd/C) gave the exo isomers 109(110-1 irC) and 110(90-92°C, 125.5-127°C, dimorphism). The basis for these stereochemical assignments remains unclear, however. Compounds... 

Benzoin can be oxidized to the a-diketone, benzii, very efficiently by nitric acid or by copper(II) sulfate in pyridine. On oxidation with sodium dichromate in acetic acid the yield is lower because some material is converted into benzaldehyde by cleavage of the bond between two oxidized carbon atoms and activated by both phenyl groups (a). Similarly, hydrobenzoin on oxidation with dichromate or permanganate yields chiefly benzaldehyde and only a trace of benzii (b). 

The compound can be prepared by direct oxidation with sodium dichromate of 2-ethyl-6-methylpyr-azine (0.10) as described by Wolt (1975b). 

If the person fails this test—determined by the extent to which the green color spreads through the tube—a more accurate Breathalyzer test is administered. The Breathalyzer test also depends on the oxidation of breath ethanol by sodium dichromate, but it provides more accurate results because it is quantitative. In the test, a known volume of breath is bubbled through an acidic solution of sodium dichromate, and the concentration of chromic ion is measured precisely with a spectrophotometer. 

Oxidation with sodium dichromate. Primary and secondary alcohols are oxidized to aldehydes and ketones in 80-90% yield by Na2Cr2 07 2H2O and sulfuric acid in DMSO at 70° (90 min.). DMSO is not involved and acts as a solvent. In its absence, considerable charring occurs with further oxidation of the carbonyl product. Cr03 can also be used as oxidant. ... 

Eq. (a) shows the oxidation ofp-nitrotoluene by sodium dichromate in an acidic medium (with H2S0 ) to yield p-nitro benzoic acid (I) whereby the methyl function in the starting material gets oxidized to the corresponding carboxylic moiety due to the evolution of 3-moles of nescent oxygen as given in Eq. (a) iii). 

Secondary alcohols are readily oxidized to ketones by sodium dichromate in sulfuric acid ( chromic acid ) or by potassium permanganate (KMn04). Primary alcohols are usually over-oxidized to carboxylic acids under these conditions. 

Q11 The oxidation of propan-2-ol, CH3CH(OH)CH3, by sodium dichromate(vi) leads to the formation of ... 

Those epimers of 1,2,3,4-tetrahydro-/5-carbolines of general structure 139, in which the hydrogen on carbon-1 ofthecarboline moiety is axial, are converted into the corrraponding 3,4-dihydro-j8-carbolinium salts (141) by mercuric acetate oxidation.i Sodium dichromate... 

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