Reduction with sodium sulfite

Most published directions for the preparation of phenylhydrazine specify the use of zinc dust and acetic acid following the reduction with sodium sulfite. No improvement in the quality or quantity of the product was obtained by using zinc and acetic acid. 

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). 

REDUCTION WITH SODIUM SULFITE Partial Reduction of Geminal Polyhalides [25 ... 

Photoreduction. Irradiation of 3,17/i-cstradiol (1) with a Hanovia mercury vapor lamp in an aqueous ethanol solution containing sodium sulfite gives as the major product 3/J,17/3-dihydroxy-5a,10)3-estrane (2). Reduction in the presence of sodium borohydride gives (3) and (4) in low yield.1 Tt is suggested that the reduction with sodium sulfite may proceed through a sulfinate intermediate. This novel photoreduction method was first observed with kynurenic acid (5), which is reduced in this way to kynurenine yellow (6).2... 

The reduction of alkyl-substituted siUcon and tin peroxides with sodium sulfite and triphenylphosphine has been reported (33,93). Alkyl-substituted aluminum, boron, cadmium, germanium, siUcon, and tin peroxides undergo oxygen-to-metal rearrangements (33,43,94), eg, equations 22 and 23. 

CuCl, especially in a single crystal form, is extensively used as an optical material for its special optical properties. Orel et al. [2] first proposed a new method to obtain CuCl particles by the reduction of Cu with ascorbic acid. Several dispersants were used in the reduction and monodispersed CuCl particles can be obtained by selecting the proper dispersant and reduction conditions. In this work, the above method was used to modify the traditional process of CuCl preparation, namely, by reducing the Cu " with sodium sulfite to obtain the highly active CuCl catalyst to be used in the direct process of methylchlorosilane synthesis. 

The most commonly employed routes for the preparation of the / -sulfatoethylsulfone group, which is the essential structural feature of vinylsulfone reactive dyes, are illustrated in Scheme 8.5. One method of synthesis involves, initially, the reduction of an aromatic sulfonyl chloride, for example with sodium sulfite, to the corresponding sulfinic acid. Subsequent condensation with either 2-chloroethanol or ethylene oxide gives the / -hydroxyethylsulfone, which is converted into its sulfate ester by treatment with concentrated sulfuric acid at 20 30 °C. An alternative route involves treatment of an aromatic thiol with 2-chloroethanol or ethylene oxide to give the /Miydroxyethylsulfonyl compound which may then be converted by oxidation into the /Miydroxyethylsulfone. 

The most feasible method consists in the reduction of diazonium salts with sodium sulfite. Although this method is given in several laboratory manuals, the results were not found entirely satisfactory. The present directions provide for a lengthy but essential heating of the diazonium-sulfite mixture, omit the useless zinc dust reduction, and supply exact details for preparation on a fairly large laboratory scale. 

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. 

Rose oxide is usually prepared from citronellol which can be converted into a mixture of two allyl hydroperoxides (e.g., by photosensitized oxidation with oxygen). Reduction of the hydroperoxides with sodium sulfite yields the corresponding diols [183]. Treatment with dilute sulfuric acid results in allylic rearrangement and spontaneous cyclization of one of the isomers a mixture of diastereoisomeric rose oxides is thus formed. The unreacted diol isomer is separated by distillation. (—)-Citronellol as the starting material yields approximately a 1 1 mixture of (—)-cis- and (—)-tra s-rose oxide. 

Addition of osmium tetroxide to norbornene 2 followed by reductive cleavage with sodium sulfite gives the exo,exo diol 3. The same reaction sequence carried out on 7,7-dimethylnorbornene 4 gives endo,endo diol 5. From these results deduce the mechanism of the addition and facial selectivity for these two substrates. 

The photo-oxidation of PE sensitized by DC A in homogeneous solution followed by reduction of the reaction mixture with sodium sulfite solution gave the ene product pinocarveol 14 and the non-ene products myrtenal 15, epoxide 16 and aldehyde 17, as shown in Fig. 21. The ene product and the non-ene products have been proposed to be derived from the energy-transfer and electron-transfer pathways, respectively [177-181], The product distributions in acetonitrile is given in Fig. 21. 

Aryl hydrazines are formed by the reduction of diazonium salts with tin(II) chloride in hydrochloric acid (Scheme 8.24). The reduction can also be achieved by treatment with sodium sulfite solution. 

Copper(I) chloride is made by reduction of copper(II) sulfate with sodium sulfite (which is produced as required from the cheaper sodium bisulfite). The white solid is left covered with the reducing solution for protection against air oxidation until it is to be used and then dissolved in hydrochloric acid. On addition of the diazonium salt solution, a complex forms and rapidly decomposes to give p-chlorotoluene and nitrogen. The mixture is very discolored, but steam distillation leaves most of the impurities and all salts behind and gives material substantially pure except for the presence of a trace of yellow pigment, which can be eliminated by distillation of the dried oil. 

Similarly, the a-monochlorinated and a-monobrominated dimethyl 2-oxoalkylphosphonates are prepared in satisfactory yields (50%) by reaction of the sodium enolate of dimethyl 2-oxoalkyl-phosphonates with NCS or NBS in DME at room temperature- "- - or with bromine in Et20 (53-71%) or THE (60%) Synthesis of diethyl l-chloro-2-oxopropylphosphonate has also been reported through reduction of the 1,1-dichloro derivatives with sodium sulfite.- lodination in the Y-position of P-ketophosphonate 1,3-dianions prepared with KiCO, in MeOH has been reported. These dianions react with benzaldehyde in a Homer-Wadsworth-Emmons-Darzens reaction sequence to produce the a,P-unsaturated a, P -epoxyketones in 60-79% yields (Scheme 7.101).s ... 

Diethyl 1-(ethoxycarbonyl)methylphosphonate, on treatment with freshly prepared sodium hypochlorite or hypobromite solution at 0°C or with chlorine under UV irradiation at 28-30°C 4 and at 50-70°C in CCI4 or with SO.CI, at 40 70"C in CIK b is converted, respectively, into the dichloro or dibromo derivatives in excellent yields. A subsequent selective reduction converts the dichloro products into the monohalo esters. Sodium sulfite is highly selective in the reduction of diethyl 1,1-dichloro-1-(ethoxycarbonyl)methylphosphonate to diethyl 1-chloro-l-(ethoxycarbonyl)methylphosphonate in high yield (90-98%). However, the dibromo ester is completely debrominated on treatment with sodium sulfite, so this method is not useful for the preparation of monobromo ester. Reduction of the dibromoester with SnCl2 (1 eq) in EtOH/H2O gives the monobromo ester in 70-85% isolated yields. ... 

Although simple isocyanates are not electrophilic enough to add to alkenes, electron-deficient isocyanates will add to alkenes. Chlorosulfonyl isocyanate is the most reactive and most commonly used isocyanate105-107. It undergoes stereospecific syn addition to alkenes. The carbonyl group adds to the most nucleophilic end of the double bond. The chlorosulfonyl group can be reductively hydrolyzed with sodium sulfite. Asymmetric induction will result from addition to... 

The action of nitric acid on diethyl 3-oxopentane-l, 5-dioate (diethyl acetonedicarboxylate, 1) was stated to yield the peroxide 2, which on reduction with sodium hydrogen sulfite gave the diester 3.31... 

Addition to aromatic ketones An extensive study of the reaction of CSI with aromatic ketones (1) presents evidence that the first step is formation of a 3-keto carboxamide (2), which can react with another molecule of CSI to form a malonamide (3). Generally, however, (2) reacts with CSI to form, after reductive hydrolysis with sodium sulfite, either an oxathiazine 2,2-dioxide (4) and/or an oxazinedione (5). The ratio of (4) to (5) depends on the keto-enol equilibrium of the intermediate (2) and on the reaction conditions. 

Phenylhydrazine is produced by diazotization of aniline and subsequent reduction with sodium hydrogen sulfite. 

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