Nitrosodisulfonate, potassium

Form Supplied in orange powder widely available. 

Handling, Storage, and Precautions in solid form, this reagent is rather unstable. It sometimes undergoes spontaneous decomposition which occasionally results in a violent explosion attributed to impurities such as chloride ion, manganese dioxide, or nitrite ion. Stored in a desiccator over calcium oxide in the presence of ammonium carbonate to provide an ammoniacal atmosphere, it is stable for several months. 

Naphthol Oxidations. a-Naphthols can be oxidized to 1,2-or 1,4-naphthoquinones by Fremy s salt. Again, the nature of the para substituent is critical. 1,4-Naphthoquinones predominate if the para position is unsubstituted. 1,2-Naphthoquinones are formed if an alkyl or aryl group occupies the para position, if there is a hydroxy group in the 2-position, or if the para position is hindered. Approximately equal amounts of 1,2- and 1,4-naphthoquinones are obtained if a hydroxy group occupies the 5-position. It has been reported that 1,4-naphthoquinones are produced from oxidation of 2- or 9-SMe substituted phenols. fi-Naphthols are generally oxidized to 1,2-naphthoquinones (eq 1).  

The methyl ether of a /3-naphthol has been reported to afford a 1,2-quinone (eq 2).  

Aniline Oxidations. 1,4-Quinones are formed by the reaction of 2,6-disubstituted and 2,3,6-trisubstituted anilines and Fremy s salt. Other ortho or meta methoxy-substituted aromatic amines were converted to the corresponding l,4-quinones and 1,2-quinones. In one case the oxidation intermediate, a quinone imine which subsequently undergoes hydrolysis to the quinone, has been isolated (eq 3).  

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Various 2,6-di8ubstituted p-benzoquinones have been prepared by oxidation of the corresponding 2,6-disubstituted phenols with potassium nitrosodisulfonate or lead dioxide in formic acid. Oxidative coupling of 2,6-disubstituted phenols to poly-2,6-disubstituted phenylene ethers followed by treatment of the polymers in acetic acid with lead dioxide is reported to give low yields of the corresponding 2,6-disubstituted p-benzoquinones. 

Hydroxylamine trisulfonates, e.g. (K03S)0N-(S03K)2 are made by the reaction of K2SO3 with potassium nitrosodisulfonate (Fremy s salt). Acidification of the product results in rapid hydrolysis to the 0,A-disulfonate which can be isolated as the exclusive product ... 

In addition to the aforementioned syntheses of various carbazole-l,4-quinone alkaloids, many formal syntheses for this class of carbazole alkaloids were also reported. These syntheses involve the oxidation of the appropriate 1- or 4-oxygenated-3-methylcarbazoles using Fremy s salt (potassium nitrosodisulfonate), or PCC (pyridinium chlorochromate), or Phl(OCCXI F3)2 [bis(trifluoroacetoxy)iodo]-benzene. Our iron-mediated formal synthesis of murrayaquinone A (107) was achieved starting from murrayafoline A (7) (see Scheme 5.34). Cleavage of the methyl ether in murrayafoline A (7) and subsequent oxidation of the resulting intermediate hydroxycarbazole with Fremy s salt provided murrayaquinone A (107) (574,632) (Scheme 5.113). 

Hydroxycarbazole gave the p-quinone (22) and 2-hydroxycarbazole the o-quinone (23) on oxidation with potassium nitrosodisulfonate. ... 

DEHYDROGENATION Dichlorodieyano-benzoquinone. Platinum catalysts. Potassium nitrosodisulfonate. Sulfuryl chloride. 

Potassium nitrosodisulfonate, 258 other methods Bis(tributyltin) oxide, 41 /-Butyl hydroperoxide-Dichlorotris-(triphenylphosphine)rutheni-um(II), 54 Dibutyltin oxide, 95 Hydrogen hexachloroplatinate(IV)-Copper(II) chloride, 145 4-Methoxy-2,2,6,6-tetramethy 1-1 -oxopiperidinium chloride, 183 of alcohols to carboxylic acids Cetyltrimethylammonium permanganate, 69... 

Potassium nitrosodisulfonate, 258 Trimethylsilyl chlorochromate, 327 By hydrolysis of acetals or thioacetals Amberlyst ion-exchange resin, 152 Methylthiomethyl p-tolyl sulfone, 192 By isomerization of allylic alcohols N-Lithioethylenediamine, 157 By oxidation of aromatic side chains Trimethylsilyl chlorochromate, 327 From oxidative cleavage of alkenes [Bis(salicylidene-7-iminopropyl)-methylamine]cobalt(II)... 

Reduction of ketone (81) with zinc and acetic acid produced the 4-hydroxypyrazoles (87), whereas reaction with dithionite gave the corresponding 1,4-dihydroxypyrazoles (88). These compounds could be oxidized with Fremy s salt (potassium nitrosodisulfonate) to the 3,4-diazacyclopentadienone 3-oxides. 

Peroxidic reagents may dehydrogenate C-8-Na. The example of this involves the conversion of isostrychnic acid (XXXIII) by hydrogen peroxide in formic or acetic acids in the presence of catalytic quantity of cobalt salt or by potassium nitrosodisulfonate, into the lactone bases CLXXIV (R = H and OH) (144, 145). In both cases, the initially formed simple 3-H indole is oxidized further, probably by way of the tautomeric enamine, to the 13-oxy derivative, which then lactonizes. 

Potassium nitrosodisulfonate (Fremy s salt), K(S03>2N0 Oxidizes phenols to yield quinones (Section 17.10). 

A solution of potassium nitrosodisulfonate (Fremy s salt) (0.56 mmol) dissolved in 5 ml water was added to a solution of the product from Step 7 (0.18 mmol) dissolved in 5 ml dioxane, the mixture stirred at ambient temperature 2 hours, and concentrated. The material was purified by reverse phase chromatography and the product isolated in 54% yield having a HPLC retention time of 1.75 minutes. 

Quinones can he prepared hy the oxidation of phenols, dihydroxy-henzenes, dimethoxyhenzenes and anilines. For example, 1,4-dihydroxy-henzene (hydroquinone) can he oxidized in good yield using sodium chlorate in dilute sulfuric acid in the presence of vanadium pentoxide and also hy manganese dioxide and sulfuric acid and hy chromic acid. Other reagents which convert hydroquinones to quinones include Fremy s salt [potassium nitrosodisulfonate, (KS03)2N0] and cerium(IV) ammonium nitrate [CAN, Ce(NH4)2(N03)J. 

Oxidations with potassium nitrosodisulfonate have been reviewed in detail. ... 

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