Procedures sulfitation

A suspension of 3.90 g (19.6 mmol) of p-(bromomethyl)benzaldehyde (2.8) and 4.00 g (31.7 mmol) of sodium sulfite in 40 ml of water was refluxed for two hours, after which a clear solution was obtained. The reaction mixture was cooled on an ice bath resulting in precipitation of some sodium sulfite. After filtration, the solvent was evaporated. Ethanol was added to the remaining solid and the suspension was refluxed for 10 minutes. After filtering the hot solution, the filtrate was allowed to cool down slowly to -18 °C whereupon sodium (p-oxomethylphenyl)methylsulfonate (2.9) separated as colourless crystals. The extraction procedure was repeated two more times, affording 2.29 g (10.3 mmol, 53%) of the desired product. H-NMR (200 MH D2O) 5(ppm) =4.10 (s,2H) 7.44 (d,2H) 7,76 (d,2H) 9.75 (s,lH). 

Procedures for determining the quaUty of formaldehyde solutions ate outlined by ASTM (120). Analytical methods relevant to Table 5 foUow formaldehyde by the sodium sulfite method (D2194) methanol by specific gravity (D2380) acidity as formic acid by titration with sodium hydroxide (D2379) iron by colorimetry (D2087) and color (APHA) by comparison to platinum—cobalt color standards (D1209). 

Another method employed is the treatment of aqueous solutions of aminophenols with activated carbon (81,82). During this procedure, sodium sulfite, sodium dithionite, or disodium ethylenediaminotetraacetate (82) is added to increase the quaUty and stabiUty of the products and to chelate heavy-metal ions that would catalyze oxidation. Addition of sodium dithionite, hydrazine (82), or sodium hydrosulfite (83) also is recommended during precipitation or crystallization of aminophenols. 

Another procedure utilizes a slurry of sodium sulfite, produced by the reaction of soda ash with sulfur dioxide, which is digested with excess sulfur until all of the sulfite is used up ... 

The procedure given above for the preparation of methanesulfonyl cyanide essentially is a combination of the sulfite reduction of a sulfonyl... 

A detailed procedure for the use of MCPBA recently appeared in Reagents for Organic Synthesis by Fieser and Fieser. The commercially available MCPBA (Aldrich) is 85% pure the contaminant, m-chlorobenzoic acid, can be removed by washing with a phosphate buffer of pH 7.5. The epoxidation is usually performed as follows a solution of 3 -acetoxy-5a-androst-16-ene (2.06 g, 6.53 mmoles) in 25 ml of chloroform (or methylene dichloride) is chilled to 0° in a flask fitted with a condenser and drierite tube and treated with a solution of commercial MCPBA (1.74 g, 20% excess) in 25 ml chloroform precooled to the same temperature. The mixture is stirred and allowed to warm to room temperature. After 23 hr (or until TLC shows reaction is complete) the solution is diluted with 100 ml chloroform and washed in sequence with 100 ml of 10% sodium sulfite or sodium iodide followed by sodium thiosulfate, 200 ml of 1 M sodium bicarbonate and 200 ml water. The chloroform extract is dried (MgS04) and evaporated in vacuo to a volume of ca. 10 ml. Addition of methanol (10 ml) followed by cooling of the mixture to —10° yields 0.8 gof 16a,17a-epoxide mp 109.5-110°. Additional product can be obtained by concentration of the mother liquor (total yield 80-90%). 

These reactions are useful because they run under mild conditions, use inexpensive or easily recoverable starting materials, and have short reaction times. The major problem in purification is the separation of the sodium pyridone sulfonate from excess sodium sulfite, sodium bromide, and sodium bromoalkyl sulfonate. However, these latter compounds usually would not interfere with the use of the pyridone sulfonate as a water tracer. From a practical point of view, the pyridone sulfonates need not be purified, but can be used directly. A modified synthetic procedure involves the treatment of the pyridone sodium salt with a tenfold excess of a,iu-dibromoalkane in acetonitrile, followed by removal of the excess dibromide by vacuum distillation. The resulting product is treated with an excess of sodium sulfite in aqueous ethanol. Evaporation of the solvent yields a useful tracer. Procedures given in the experimental section were... 

Arenesulfinate esters are usually prepared from an arenesulfinyl chloride and an alcohol in ether and pyridine. The arenesulfinyl chloride is usually prepared from the sodium arenesulfinate which is made by reduction of the arenesulfonyl chloride, preferably by aqueous sodium sulfite. After the crystalline sulfinate epimer has been removed by filtration, the equilibrium between the epimers remaining in the mother liquor may be reestablished by the addition of hydrogen chloride as shown by Herbrandson and Cusano . In this way the yield of the least soluble diastereomer may be increased beyond that which exists in the original reaction mixture (Scheme 1). Solladie prepared sulfinate ester 19 in 90% yield using this technique and published the details of his procedure. Estep and Tavares also published a convenient recipe for this method, although their yields were somewhat lower than Solladie s. 

Taurine is generally prepared from ox bile1 or the large muscle of the abalone.2 It has been synthesized from isethionic add through chloroethanesulfonic acid followed by the action of aqueous ammonia 3 from ethyleneimine and sulfur dioxide 4 from 2-mercaptothiazoline by oxidation with bromine water 5 from bromoethylamine and ammonium sulfite 6 and from acetaldehyde by a complex set of reactions involving sulfonation, formation of the aldehyde ammonia and the imido sulfonic add and finally reduction.7 The method given in the procedure has recently appeared in the literature.8 9... 

The total iodine procedure is claimed to be relatively free from interference by foreign ions. The iodate procedure is subject to interference by bromate and sulfite ions. This method is claimed to be capable of determining down to 0.1 ig iodine in the presence of 500 mg chloride ion and 5 mg of bromide ion. 

Any sulfate ions resulting from oxidation of sulfite should be removed otherwise they will be converted to sulfuric acid in the subsequent procedure and destroy sultone. Ordinarily, 12-13 g. of barium chloride dihydrate is required. The end point of the addition is conveniently determined with tetrahydroquinone indicator used in spot tests on filter paper [cf. Ind. Eng. Chem., Anal. Ed., 9, 331 (1937)]. 

The checkers found that the procedure of Helberger and Lan-terman,2 which avoids the use of an ion-exchange resin, is also satisfactory in case it is regarded as inconvenient to set up the resin column. According to this procedure, after completion of the reaction with sodium sulfite, anhydrous hydrogen chloride is passed into the hot solution to liberate sulfur dioxide. After removal of sulfate as in the described procedure, the undiluted aqueous solution is saturated with hydrogen chloride gas at a temperature below 25°. The precipitated sodium chloride is removed by suction filtration, the filter cake is... 

The cyclic sulfites were first found to react with lithium phenoxides as nucleophiles in DMF in a one-pot procedure commencing from the unprotected diol [357]. Subsequent work opened up this class of donor to alcohol nucleophiles in conjunction with the use of a Lewis add, such as Yb(OTf)3 or Ho(OTf)3, to activate the donor in refluxing toluene (Scheme 4.57) [314,358,359]. The very high degree of P-selec-tivity observed in these reactions is consistent with an SN2-like displacement of the sulfite oxygen. 

Determination of sulfite - Part 1 Optimized Monier Williams procedure... 

There are several potential sources of error in these methods. The filters routinely used have a relatively high and somewhat variable sulfate content, so that, at concentrations lower than 10 Mg/m and sampling periods less than 24 h, the reliability of tlie sulfate measurement is reduc. Several different types of filtering media adsorb sulfur dioxide during the ftrst few hours of sampling this alters the amount of sulfate observed. This interference can become critical when sampling periods are less than 24 h and the concentration ratio of sulfur dioxide to sulfate is greater than 5 1. Interference can also be introduced by hot-water extraction when reduced sulfur compounds like sulfite are present, because they are oxidized to sulfates in this process. Another possible error source is that some of the various analytic procedures us for sulfate determination may be influenced by other substances also present in the particulate matter. 

More abundant are reductions with sodium sulfite which is applied in aqueous solutions (solubility 24%). Its specialties are reduction of peroxides to alcohols [257], of sulfonyl chlorides to sulfinic acids [252], of aromatic diazonium compounds to hydrazines [253], and partial reduction of geminal polyhalides [254] Procedure 43, p. 216). 

Because wood sugar solutions are sterile, they permit yeast to survive under conditions that are suitable for reuse of the yeast. This procedure is similar to that used in the fermentation of sulfite liquor at the Mechan-icsville. New York, plant as early as 1913 and in Swedish and German processes since that time. Yeast reuse has also been employed for sulfite waste liquor in Canada. ... 

Commercial copper bromide or its dimethyl sulfide complex contains impurities that are deleterious to the reaction. Therefore, the copper(l) bromide-dimethyl sulfide complex is prepared according to the method of House from copper(l) bromide generated by reduction of copper(ll) bromide (Aldrich Chemical Company, Inc., 99%) with sodium sulfite. Best results ctre obtained using copper(l) bromide-dimethyl sulfide complex freshly recrystallized according to the following procedure. 

Contraindications Ophthalmic solutions (both strengths) of phenylephrine HCl are contraindicated in patients with anatomically narrow angles or narrow-angle glaucoma, severe arteriosclerotic cardiovascular or cerebrovascular disease, use during intraocular operative procedures when the corneal epithelial barrier has been disturbed, and in persons with a known sensitivity to phenylephrine, sulfites, or any of its components including preservatives. The 10% solution is contraindicated in patients with aneurysms. 

Similar surfactants based upon glucopytanose were synthesized using the Gao and Sharpless procedure for preparation of the cyclic sulfate from methyl a-D-glucopyranoside 252 using a mixture of DMF and ethyl acetate (1 1) as solvent, the axial cyclic sulfite 253 was formed exclusively, as indicated by H NMR spectroscopy, from which the cyclic sulfate 65 was obtained in good yield (Scheme 42) <1999S621>. 

The chemical transformation must not affect the stereogenic centers. Suitable acyclic candidates are compounds with easily convertible functional groups, such as diols, diamines, amino alcohols, dicarboxylic acids and so on. A number of procedures known before 1973 have been compiled, including conversion of diols and amino alcohols into sulfites or 1,3-dioxolanes by thionyl chloride, or acetalization with ketones31,1"319, as well as the conversions of dinitriles into imides320, dicarboxylic acids into cyclic anhydrides or imides321, and hydroxy acids into oxazolidones 322. 

N) Ditto, Vol 3. Supplement Number One to Volume 1 (1943). Chap I (Analysis of acids including i Ilu strati on s of Berl pipette and Weighing pipette used at Keystone Ordn Works, Meadville, Pennsylvania) Chap II (Various laboratory procedures) Chap IV (Analysis of toluene used for manuf TNT) Chap V (Analysis of TNT) Chap VI [Analysis of Sellite (Na sulfite soln) used for purification of crude TNT] Chap VI [Analysis of "soda ash (crude Na carbonate)] Chap VI [Analysis of brimstone (crude sulfur) used for manuf sellite] Chap VII [Analysis of Tri-Oil (crude TNT), yellow waters, and red waters formed during manuf of TNT] ... 

Preparation of Cyclic Sulfites Using 1,2- or 1,3-Diols According to Procedure 2-2... 

The first report on sulfites appeared in 1846, and several synthetic procedures were published later, in 1858-1859 [1]. The literature contains numerous reports on sulfites from 1909 to the present. Sulfites have not even been mentioned briefly in some well-known texts on sulfur chemistry. However, the first comprehensive review appeared in 1963 in Chemical Reviews [1]. Sulfites are characterized by the structure (I) where R = aryl or alkyl groups. The... 

Table III lists the alcohol used, the yields of sulfites obtained, and their physical properties in a similar procedure.

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