Sodium hydrogensulfite

For the in situ preparation of the required arenediazonium salt from an aryl amine by application of the diazotization reaction, an acid HX is used, that corresponds to the halo substituent X to be introduced onto the aromatic ring. Otherwise—e.g. when using HCl/CuBr—a mixture of aryl chloride and aryl bromide will be obtained. The copper-(l) salt 2 (chloride or bromide) is usually prepared by dissolving the appropriate sodium halide in an aqueous solution of copper-(ll) sulfate and then adding sodium hydrogensulfite to reduce copper-(ll) to copper-(1). Copper-(l) cyanide CuCN can be obtained by treatment of copper-(l) chloride with sodium cyanide. 

Maleic acid monoester Sodium hydrogensulfite Sodium hydroxide... 

A more recent synthesis proceeds via 2,5-diarylamino-3,6-dicarbethoxy-l, 4-hy-droquinone 65, which is obtained by reducing 2,5-diarylamino-3,6-dicarbethoxy-1,4-benzoquinone 64 with sodium hydrogensulfite or sodium in ethanol ... 

FLD (Xj,=335nm Xj j=389nm) post-column derivatization with sodium hydrogensulfite... 

Potassium permanganate (4.59 g) was then slowly added and the mixture stirred for 2 hours on an iced bath for 18 hours at ambient temperature. The solution was then treated with 720 ml of ethyl acetate, 540 ml of water, and sodium hydrogensulfite and the pH raised to 1 using 1.0 M hydrochloric acid. The organic layer was separated and washed three times with 1.0 M hydrochloric acid and then concentrated and the residue washed successively with 600 ml of water, 600 ml of methanol, and three times with 600 ml of water. The residue was then dissolved in THF and reprecipitated in excess methanol, dried, and 5.30 g of product isolated having an Mn of 13,200 Da with an Mw of 18,300 Da and containing 8 mol% carboxylic acid. 

Vat cotton, rayon, and wool water-insoluble dyes solubilized by reducing with sodium hydrogensulfite, then exhausted on fiber and reoxidized anthraquinone (including polycyclic quinones) and indigoids... 

The biosynthesis of uracil proceeds via decarboxylation of orotidin-5 -phosphate, which is formed from carbamoyl phosphate and aspartate via orotate after nucleosidation with 5-phosphoribosyl-l-diphosphate. Uracil can also be generated from cytosine by oxidative deamination using sodium hydrogensulfite. 

Atoms, ions and particles that have a deficiency of electrons are called electrophiles, and will seek out areas of high electron density, i.e. the 8 of the O of the CO bond. Such reagents are quite numerous in chemistry and are very useful. The ones particularly useful for carbonyl compounds include the negatively polarised parts of H-CN (hydrogen cyanide) H-NH2 (ammonia and related compounds) and Na HSO (sodium hydrogensulfite) (Figure 7.2.5). 

Addition reactions with sodium hydrogensulfite, NaHSOs... 

In sodium hydrogensulfite the attacks the electron rich area at the O of the aldehyde or ketone C=0 bond. The remainder of the compound adds to the C of the C=0 (Figure 7.2.8). The resulting compound is crystalline. 

Reaction of the piperidinium salt of the dithiobenzoic acid (260) with equimolar amounts of chloroacetaldehyde as its sodium hydrogensulfite adduct (261) followed by an acid-catalyzed cycli-zation gives access to 2-phenyl-1,3-dithiolylium tetraphenylborate (262) (Equation (44)) <75S277>. 

Generally, sodium hydrogensulfite addition products of higher molar mass aldehydes can be precipitated easily. Hence NaHS03 is often used to separate aldehydes from mixtures. 

What is the molar mass of the ketone of which 0.2 mole of its addition product with sodium hydrogensulfite weighs 35.2 grams ... 

The oxidation of glycerol in the presence of Acetobacter xylinum gives the ketotriose 2, which can be separated as its insoluble sodium hydrogensulfite addition compound, and then, recovered on acidification. The dimer, mp 82°, is obtained on crystallization from ethanol but, on standing, higher-melting products are deposited from the mother liquor.17 The 1-phosphate has been synthesized.18... 

Sodium hydrogensulfite reacts with starch dialdehyde in a 1 1 ratio.527,528 Despite the fact that aldehydes react with hydrogensulfites, these compounds are described as adducts. Sodium sulfite degrades starch dialdehyde and the glyoxal liberated forms tetrahydrobenzoquinone.529... 

To a stirred mixture of 40% sodium hydroxide solution (1 mL) and sodium hypochlorite solution, prepared from chlorine gas and sodium hydroxide (1.84 g) in ice water (15 mL), was added a solution of 3-acetyltropolone (820 mg, 5 mmol) in 6% NaOH solution (3 mL) with cooling in an ice water bath. The reaction mixture was stirred for 1 hr at 15 °C. The mixture was added to a solution of sodium hydrogensulfite (500 mg) in water (2 mL) to remove an excess of sodium hypochlorite. The mixture was carefully made slightly acidic with concentrated hydrochloric acid. The precipitate was collected and dissolved in hot water, the solution was made acidic with concentrated hydrochloric acid to give crystals which were recrystallized from methanol to give 3-carboxytropolone as yellow needles in a yield of 690 mg (85%), mp 217-218 °C IR (KBr) vmax 3212 (OH), 1718 (COOH), 1585 cm-1 (C=0) H NMR (deuteriochloroform) 8 7.05-7.8 (3H, m), 8.15 (1H, i,J= 10 Hz, H-4), 10.3 (2H, br, OH). 

Triketohydrindene hydrate can be prepared by dissolving 0.15 g ninhydrin to 10 mL sodium hydrogensulfite (12.5%). 

Mono- or dialkyl esters of succinic acid are formed by the addition of fatty alcohols or ethoxylated fatty alcohols to maleic anhydride in the presence of acid catalysts. These are the hydrophobic starting material for sulfosuccinates. The next step is the addition of sodium hydrogensulfite in aqueous methanol, which forms the surface-active sulfosuccinates via a radical reaction. 

E 220 Sulfur dioxide (plus sodium sulfite, sodium hydrogensulfite, sodium metabisulfite , potassium metabisulfite, calcium sulfite, calcium hydrogensulfite)... 

For example, mesoionic 2-[2-(isopropenylcarbonyloxy)ethylthio]-l-methyl-6-oxo-3-phenyl-5-propyl-l,6-dihydro-pyrimidin-3-ium-4-olate (11) (34) was stirred in equimolar amoimt with a solution of RAMEB for 5 days at ambient temperature. The 2 1 hosfc-guest complex 11/RAMEB was isolated in 71% srield relative to the guest monomer. The water solubility of complex was about 800 mg in 1-ml water at ambient temperature. The radical polymerization of RAMEB-complexed monomer was carried out with 3.3 mol% of redox initiator potassiiun peroxodisul-fate and sodium hydrogensulfite. According to the results of the gel-permeation chromatography (GPC) obtained for the polymer prepared from the imcomplexed monomer, 85% of 11 was unreacted after 1 h. Additionally, the molecular weight distribution of the polymer synthesized without RAMEB is bimodal with = 11,000 g/mol and polydispersity of 4.5 (35). 

Both C-atoms are able to attract nucleophilic compounds. Thiols (R-SH) for instance link preferably to C-1, forming B-mercapto-propionaldehyde (R-S-CH2-CH2-CHO). Sodium hydrogensulfite occupies not only C-1, but also C-2. Apparently acrolein is highly reactive and accordingly highly effective and may be defined as a biocide rater than a microbicide. hydrogensulfite occupies not only C-1, but also C-2. 

Chloroacetaldehyde exhibits bactericidal and fungicidal efficacy. Mainly in use is the addition product of sodium hydrogensulfite and chloroacetaldehyde, as it is easily to handle and nearly odourless. Worth mentioning is its use in ground disinfectants. 

Two other frequently used metal salts are Cu CN and Zn( CN)2. The former is readily accessible in crystalline form in 80-90% yield by treatment of a weakly basic aqueous solution of sodium or potassium cyanide with excess CUSO4 5H2O in the presence of sodium hydrogensulfite at 20-60°C in radiochemical yields of 80-90%. The latter is conveniently obtained as a white precipitate in 90% yield upon treatment of an aqueous solution of with ZnCl2. ... 

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