Reduction with stannous chloride

Aniline 77 was converted into its diazonium salt with nitrous acid and this was followed by reduction with stannous chloride to afford the corresponding arylhydrazine 78. Condensation of 78 with 3-cyanopropanal dimethylacetal 79 gave the arylhydrazone 80. Treatment of 80 with PPE resulted in cyclization to indole 81. The nitrile group was then reduced to the primary amine by catalytic hydrogenation. Reaction of the amine with excess formalin and sodium borohydride resulted in Imitrex (82). 

Alloxantin has been obtained by the oxidation of uric acid with nitric acid, followed by reduction with hydrogen sulfide 2 by oxidation of uric acid with potassium chlorate, followed by reduction with stannous chloride by condensation of alloxan with dialuric acid in aqueous solution and by oxidation of dialuric acid. ... 

In the latter case the structure was established by reduction with stannous chloride in acetic acid, which afforded the imidazole derivative (104), thus proving ortho substitution, followed by comparison of the ultraviolet spectrum of 104 with the two possible benzimidazole derivatives of carbazole. Deamination of 103 via diazotization in sulfuric acid afforded 1-nitrodibenzothiophene (105) (54%), being the only recorded route to this compound (Scheme 5). Initial attempts to hydrolyze 102 to the nitroamine (103) had been made with ethanolic hydrogen chloride... 

Compared with tin stannous chloride is only one half as efficient since it furnishes only two electrons per mole (tin donates four electrons). This disadvantage is more than offset by the solubility of stannous chloride in water, hydrochloric acid, acetic acid, alcohols and other organic solvents. Thus reductions with stannous chloride can be carried out in homogeneous media (Procedure 36, p. 214). 

Generally primary nitro compounds are reduced to aldoximes and secondary to ketoximes by metal salts. On reduction with stannous chloride 1,5-... 

REDUCTION WITH STANNOUS CHLORIDE Deoxygenation of Sulfoxides [186]... 

Naphthaldehyde has been made from a-naphthonitrile by reduction with stannous chloride, and from naphthalene by the action of aluminum chloride, hydrogen cyanide, and hydrochloric acid. The best preparation is the Sommelet reaction from a-chloro- or a-bromomethylnaphthalene and hexamethylenetetramine in aqueous alcohol is.is. .is.w or glacial acetic acid. This method has been improved in the present procedure by the use of 50% acetic acid as solvent. 

The preparation of ethyl a-azoxyisopropyl ketone is a typical example of the bimolecular reduction with stannous chloride [37]. 

On reduction with stannous chloride it yielded 3-aminoperchloryl benzene, in the form of colourless needles, m.p. 30-31°C. By acetylation with acetic anhydride and acetic acid it yielded 3-perchlorylacetanilide (m.p. 136-137°C). 

STEPHEN ALDEHYDE SYNTHESIS. Preparation of aldehydes from nitriles by reduction with stannous chloride in ether saturated with hydrochloric acid. The intermediate aldimine salts have to be hydrolyzed. The best results are obtained in the aromatic series. 

Reduction with stannous chloride and hydrochloric acid pio ceeds easily in the cold. 

Reduction with stannous chloride and hydro chloric acid takes place with difficulty and ouly in the hot A zincs. 

Cyclooxygenase catalyzes the first step in the biosynthesis of arachidonic acid to PGH2. PGF2a produced from PGH2 by reduction with stannous chloride, is measured by enzyme immunoassay. This assay is based on the competition between PGs and... 

The best general procedure for preparing 2-substituted phenox-azines is the pyrolytic condensation of o-chloronitrobenzene derivatives with sodium o-bromophenolate,20,29 followed by reduction with stannous chloride or with iron filings in acetic acid and subsequent cyclization of the ether 10. If the ether 10 is previously A-formylated,... 

Reduction with Stannous Chloride. A solution of 20 grams of the purified dye in 250 to 300 cc. water is heated to boiling in a round-bottomed flask fitted with reflux condenser and stirrer. A solution of 40 grams of stannous chloride in 100 cc. concentrated hydrochloric acid (1.19) is added and the mixture is boiled for 3 hours. If the solution is still not completely decolorized, more of the stannous chloride solution is added. 

On heating with ethyl chloride or bromide and alcohol in presence of alcoholic potash, an ether is formed. On reduction with stannous chloride or zinc-powder and caustic soda, the ether undergoes an intramolecular change, a sulphonic acid of ethoxy-benzidine, of the constitution ... 

For the quantitative estimation the nitrometer method is not in general applicable, though the nitramine group in tetiyl responds to this test. The Dumas method may be used under precautions, and the Kjeldahl method is sometimes used for the lower nitrocompounds. Titration methods depending on reduction with stannous chloride are described by Limpricht,... 

Sandin and Fieser developed an efficient synthesis of the potently carcinogenic 9,10-dimethyl-l,2-benzanthracene from 1,2-benzanthraquinone (1) involving addition of methyl Grignard reagent, reaction of the adduct (2) with hydriodic acid to give the 9-methyl-10-iodomethyl derivative (3) and reduction with stannous chloride in dioxane-hydrochloric acid. 

Cleavage of N-nitrosoamines. Buck and Ferry purified N-ethyl-m-toluidine by conversion into the N-nitroso derivative and cleavage of this by reduction with stannous chloride. 

Since decomposition of tetrasulphur tetranitride with alkali gives ammonia, and reduction with stannous chloride followed by decomposition with alkali also gives ammonia, there canbe no NN links in molecule. 

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