Sodium bismuthate

Sodium bismuthate NaBi03 is a stable solid compound of rather ill-defined composition, which is commercially available as a yellow to light brown powder and normally used without purification. The commercial product is suggested to be a mixture of dibismuth pentaoxide, sodium carbonate and sodium peroxide. Hence, commercial samples are often variable in appearance and reactivity. 

Sodium bismuthate is usually employed as a suspension in the aqueous media or organic solvents acidified with acetic or phosphoric acid. It cleaves 1,2-glycols or related alcohols to the corresponding carbonyl compounds. 

Phenols and olefins are oxidized to polyphenylene oxides and v/c-diol derivatives, respectively. 

The reaction can be carried out in the presence of acetic or phosphoric acid at room temperature. Alcohols such as methanol and ethanol can be employed as the reaction media, since they are oxidized quite slowly with sodium bismuthate. Anhydrous conditions, as required in the use of lead tetraacetate, are not necessary for sodium bismuthate [50JCS(C)1907, 66RPA185, 67AP(300)520, 70AP(303)233]. 

The mechanism of 1,2-cleavage of glycols with sodium bismuthate is generally considered to be similar to that with lead tetraacetate and periodic acid [40CB563], although there is still some controversy [50JCS(C)1907]. A cyclic bismuthate diester is postulated as a plausible intermediate, though the rates of oxidation observed are not so different between cis- and trans-, 2-cyclohexanediols. 

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Sodium bismuthate (oxidation of manganese) heat 20 parts of NaOH nearly to redness in an iron or nickel crucible, and add slowly 10 parts of basic bismuth nitrate which has been previously dried. Add 2 parts of sodium peroxide, and pour the brownish-yellow fused mass on an iron plate to cool. When cold break up in a mortar, extract with water, and collect on an asbestos filter. 

Other methods of preparing tertiary bismuthines have been used only to a limited extent. These methods iaclude the electrolysis of organometaUic compounds at a sacrificial bismuth anode (54), the reaction between a sodium—bismuth or potassium—bismuth alloy and an alkyl or aryl haUde (55), the thermal elimination of sulfur dioxide from tris(arenesulfiaato)bismuthines (56), and the iateraction of ketene and a ttis(dialkylainino)bismuthine (57). 

A variety of oxidative reagents can be used to convert 17-hydroxypregnanes containing an additional oxygen function at C-20 into 17-ketoandrostanes. Among the most widely used have been chromium trioxide, lead tetraacetate, periodic acid and sodium bismuthate. 

Sodium Bismuthate Degradation To a solution of 9a,llj5-dichloro-17a,21-dihydroxypregna-l,4-diene-3,20-dione (1 g) in 50% aqueous acetic acid (800 ml) is added sodium bismuthate (18 g) and the suspension is stirred at room temperature for 20 hr. The reaction mixture is then filtered... 

Serini reaction, 167 Simmons-Smith reaction, 107 Sodium acetylide, 138 Sodium bismuthate, 147, 149 Sodium bistrimethylsilylamide, 90 Sodium chloroacetylide, 68 Solvolytic cleavage of cyclic ethers, 267 3- (5 -Spiro-2, 2 -dimethyloxazolidi nyl) -cholestane, 360... 

Iodine is also given off to a small extent in dissolving the uranium metal in nitric acid, but larger amounts may be obtained on steam distillation after dissolution (5). Ruthenium is often removed from the fission products by distillation of the volatile tetroxide formed by oxidation with potassium permangate, sodium bismuthate, periodic acid (38) etc. The distillation goes readily and gives a product of good purity. 

Carnot s reagent chem A solution of sodium bismuth thiosulfate in alcohol used for determining potassium. kar noz re a ant ... 

System (2) has been described for the assay of corticosteroids (cortisone, hydrocortisone, prednisone, and prednisolone) in urine [141]. Prior to introduction into the GC system, the sample was eluted with 2 1 ethyl acetate-methanol, the extracts evaporated to dryness, and then oxidized with sodium bismuthate. Used in the method was a silanized column (132 cm X 5 mm) containing 2,2-dimethylpropane-l,3-diol adipate (0.65%) supported on celite, and operated at 230°C. The carrier gas was argon, and the detector used strontium 90-ionization. The standard deviation was 3.5 % (based on 47 determinations). 

System (3) has been recommended for the separation and determination of 17,21-dihydroxy-20-oxosteroids, including cortisone [142], Prior to introduction into the GC system, treatment with sodium bismuthate in acetic acid at room temperature was performed, followed by addition of aqueous NaOH. The analytes were then extracted with chloroform. The column used was glass column (6 ft x 0.25inch), containing 3% QF-1 on GasChrom Q (100 to 120 mesh), operated at 225°C. Argon (150 mL/min) was used as the carrier gas, and detection was based on a P-ionization detector. It was reported that results obtained with a 1 1 mixture of cortisone and hydrocortisone were accurate to within approximately 1%. 

System (4) has been reported for the quantitative determination of steroids in health and disease [143], Prior to analysis, free steroids were removed from the sample. Conjugated steroids were enzymatically hydrolyzed, and the liberated products extracted into 1 3 tetrahydrofuran-ethyl ether. The extract was evaporated, the residue dissolved in acetic acid, and then oxidized with sodium bismuthate. The final product was acetylated or formulated, and subjected to GC analysis along with the standard. A stabilized column of 4% LAC-2R-446 and 1% 85% phosphoric acid on... 

Solid sodium bismuthate (NaBi03) has an oxidizing strength similar to that of Ag2+ and S201. Excess solid oxidant is removed by filtration. 

Bismuth Arsenite.—When arsenious acid acts upon a solution of sodium bismuth chloride, a white precipitate of approximate composition BiAsO3.5H20 is formed.6 The substance has not been obtained pure. It is not decomposed by boiling aqueous alkali 7 it is soluble in nitric acid.8... 

Sodium bismuthate reacts with 1 (47, 52), as does BiON03 (46). Methyl exchange between Cr(II) and 1 follows second-order kinetics (55) the rate constant was 360 30M sec-1, and values for the activation parameters A H and A 5 were 15.9 0.9 kJ mol-1 and -144 J mol-1 K respectively. Ferric compounds are reported to demethylate 1 (30, 31, 37). Cupric nitrate gives no noticeable reaction by itself with 1 (46, 54), but de-methylation proceeds readily in the presence of high chloride or bromide concentrations (>2 M). Methyl chloride and methyl bromide formed as products. When ethanol was used as solvent, methyl ethyl ether also formed as product (54). An unstable intermediate CH3CuC1 may form as... 

The occurrence of a similar reaction has recently been indicated by studies carried out in this laboratory (7). If p-hydroxybenzyl alcohol (XXXVI) was oxidized with sodium bismuthate, the spirocyclic epoxy-cyclohexadienone (XXXVII) was obtained. The epoxide ring of this compound was hydrolyzed almost instantaneously by 2N aqueous hydrochloric acid and in a few hours by 10% aqueous acetic acid. However, the expected glycol (XXXVIII) could not be isolated since it decomposed immediately into equimolar amounts of hydroquinone and formaldehyde. (Attempts are now being made to prepare compounds analogous to XXXVIII but containing, in addition to the HOCH2 group, a carbon sub-... 

Keywords oxime, semicarbazone, silica gel, sodium bismuthate, microwave irradiation, ketone... 

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