Stannous chloride hydroxide

Reduction of methyl orange to />-aminodimethylaniline. Method 1. Dissolve 2 0 g. of methyl orange in the minimum volume of hot water and to the hot solution add a solution of 8 g. of stannous chloride in 20 ml. of concentrated hydrochloric acid until decolourisation takes place gentle boiling may be necessary. Cool the resulting solution in ice a crystalline precipitate consisting of sulphanilic acid and some p-aminodimethylaniline hydrochloride separates out. In order to separate the free base, add 10 per cent, sodium hydroxide solution until the precipitate of tin hydroxide redisaolves. Extract the cold solution with three or four 20 ml. portions of ether, dry the extract... 

The crude o-phenylenediamine may be converted into the dihydrocliloride and the salt purified in the following manner. Dissolve it in 60 ml. of concentrated hydrochloric acid and 40 ml. of water containing 2 g. of stannous chloride, and treat the hot solution with 2-3 g. of decolourising carbon. Filter, add 100 ml. of concentrated hydrochloric acid to the hot colourless filtrate, and cool in a freezing mixture of ice and salt. Collect the colourless crystals of the dihydrochloride on a Buchner or sintered glass funnel, wash with a small volume of concentrated hydrochloric acid, and dry in a vacuum desiccator over sodium hydroxide. The yield is 61 g. 

A sodium stannite solution was prepared by addition of aqueous sodium hydroxide (2.5 mol, lOOg) to aqueous stannous chloride (0.25 mol, 56g). The initially formed precipitate redissolved to form a clear solution. This solution was gradually added to a solution of 16.3g (0.1 mol) phenyl-2-nitropropene in THF at room temperature. A slightly exothermic reaction ensued, and the reaction mixture was stirred for 30 min, a saturated sodium chloride solution was added, and the solution was extracted with ether and the pooled extracts were evaporated under vacuum to give essentially pure P2P oxime in 80% yield. 

Stannic and stannous chloride are best prepared by the reaction of chlorine with tin metal. Stannous salts are generally prepared by double decomposition reactions of stannous chloride, stannous oxide, or stannous hydroxide with the appropriate reagents. MetaUic stannates are prepared either by direct double decomposition or by fusion of stannic oxide with the desired metal hydroxide or carbonate. Approximately 80% of inorganic tin chemicals consumption is accounted for by tin chlorides and tin oxides. 

Stannous Chloride Dihydrate. A white crystalline soHd, stannous chloride dihydrate is prepared either by treatment of granulated tin with hydrochloric acid followed by evaporation and crystallisation or by reduction of a stannic chloride solution with a cathode or tin metal followed by crystallisation. It is soluble in methanol, ethyl acetate, glacial acetic acid, sodium hydroxide solution, and dilute or concentrated hydrochloric acid. It is soluble in less than its own weight of water, but with much water it forms an insoluble basic salt. 

Stannous Oxide Hydrate. Stannous oxide hydrate [12026-24-3] SnO H2O (sometimes erroneously called stannous hydroxide or stannous acid), mol wt 152.7, is obtained as a white amorphous crystalline product on treatment of stannous chloride solutions with alkaH. It dissolves in alkaH solutions, forming stannites. The stannite solutions, which decompose readily to alkaH-metal stannates and tin, have been used industrially for immersion tinning. 

Staono-. stannous, stanno-, tin(II). -azetat, n. stannous acetate, tin(II) acetate, -chlorid, n. stannous chloride, tin(II) chloride, -chlor-wasserstoffsMure, /. chlorostannous acid, -hydroxyd, n. stannous hydroxide, tin(II) hydroxide. -jodid, n. stannous iodide, tin(II) iodide. -jodwasserstoffsaure, /. iodostannous acid, -oxyd, n. stannous oxide, tin(II) oxide, -salz, n. stannous salt, tin(II) salt, -sulfid, n. stannous sulfide, tin(II) sulfide. -verbindung, /, stannous compoimd, tin(II) compound,... 

It is advisable to test a small portion of the filtrate for platinum by acidifying with hydrochlorio acid and adding a few drops of stannous chloride solution a yellow or brown colour develops according to the quantity of platimun present. The yellow colour is soluble in ether, thus rendering the test more sensitive. If platinum is foimd, treat the filtrate with excess of formaldehyde and sodium hydroxide solution and heat platinum black separates on standing and may be filtered and worked up with other platinum residues (see Method 3). 

Samples are hydrolyzed with hydrochloric acid and stannous chloride solution at elevated temperature, and the evolved carbon disulfide is drawn with an air steam through two gas washing tubes in series containing lead acetate and sodium hydroxide solutions and an absorption tube containing an ethanolic solution of cupric acetate and diethanolamine. Lead acetate and sodium hydroxide remove hydrogen sulfide and other impurities. In the absorption tube, the carbon disulfide forms two cupric complexes of Af,Af-bis(2-hydroxyethyl)dithiocarbamic acid with molecular ratios Cu CS2 of 1 1 and 1 2. These complexes are measured simultaneously by spectrophotometry at 453 nm. 

Sodium hydroxide, 10% in water. Dissolve 10 g of NaOH in 100 mL of distilled water Lead acetate, 30% in water. Dissolve 30 g of acetate in 100 mL of distilled water Stannous chloride solution. Dissolve 40 g of reagent in 100 mL of concentrated hydrochloric acid... 

Diaminopyridine has been prepared by reduction of 2-amino-3-nitropyridine with iron and aqueous acidified ethanol,3 tin and hydrochloric acid,6 or stannous chloride and hydrochloric acid,6 by catalytic reduction of 3-amino-2-nitropyridine,6 by reduction of 3-amino-2-nitropyridine,7 2-amino-5-chloro-3-nitro-pyridine,8 or 2-amino-5-bromo-3-nitropyridine 4 with sodium hydroxide solution and an aluminum nickel alloy, and by catalytic reduction of 2-amino-5-bromo-3-nitropyridine.4 Animation of... 

Sato et al. carried out detailed studies on the possibilities of transformation of tetrazolo[l,5-tf]pyrazines 54 to 2-aminopyrazines 56 < 1994S931 >. These authors found that the generally used methods for this conversion fail because the starting compound exists in the stable bicyclic form 54, whereas partial formation of the azide valence bond isomer 55 would be necessary for the success of the transformation. Application of special reaction conditions succeeded, however hydrogenation over palladium catalyst in the presence of ammonium hydroxide or treatment with stannous chloride in a mixture of methanol and hydrochloric acid solved this problem. Thus, a great number of derivatives of 54 was reduced to the corresponding 2-aminopyrazine 56 in medium to high yields (45-100%). 

As Umezaki and Iwamoto [42] have reported that organic mercury can be reduced directly with stannous chloride in the presence of sodium hydroxide and copper II, the determination of organic mercury can be simplified, particularly if the reagent used for back-extraction does not interfere with the reduction of organic mercury. Matsunga and Takahasi [43] found that extraction with an ammoniacal glutathione solution was satisfactory. 

Experiments—Dissolve 3 g. of helianthine in the minimum amount of hot water and add hot stannous chloride solution (8 g. in 20 c.c. of concentrated hydrochloric acid) until decolorisation takes place. On cooling and rubbing with a glass rod sulphanilic acid crystallises. After some time collect it at the pump. Add excess of concentrated alkali hydroxide solution to the filtrate and extract it with ether. 

The reduction of a dinitro ketone to an azo ketone is best achieved with glucose. 2,2 -Dinitrobenzophenone treated with glucose in methanolic sodium hydroxide at 60° afforded 82% of dibenzo[c,f [i 2]diazepin-l 1-one whereas lithium aluminum hydride yielded 24% of bis(o-nitrophenyl)methanol [575], Conversion of aromatic nitro ketones with a nitro group in the ring into amino ketones has been achieved by means of stannous chloride, which reduced 4-chloro-3-nitroacetophenone to 3-amino-4-chloroacetophenone in 91% yield [178]. A more dependable reagent for this purpose proved to be iron which, in acidic medium, reduced m-nitroacetophenone to m-aminoacetophenone in 80% yield and o-nitrobenzophenone to o-aminobenzophenone in 89% yield (stannous chloride was unsuccessful in the latter case) [903]. Iron has also been used for the reduction of o-nitrochalcone, 3-(o-nitrophenyl)-l-phenyl-2-propen-l-one, to 3-(o-aminophenyl)-l-phenyl-2-propen-l-one in 80% yield [555]. 

Complete deoxygenation of quinones to hydrocarbons is accomplished in yields of 80-85% by heating with a mixture of zinc, zinc chloride and sodium chloride at 210-280° [932]. Refluxing with stannous chloride in acetic and hydrochloric acid followed by refluxing with zinc dust and 2 N sodium hydroxide reduced 4 -bromobenzo[5. 6 1.2]anthraquinone to 4 -bromo-benzo[5. 6 1.2]anthracene in 95% yield [181], and heating with iodine, phosphorus and 47% hydriodic acid at 140° converted 2-chloroanthraquinone to 2-chloroanthracene in 75% yield [222]. Also aluminum in dilute sulfuric add can be used for reductions of the same kind [151]. 

The bimolecular reduction of aromatic nitro compounds, depending on reaction conditions, may produce azoxy compounds, azo compounds, hydrazo compounds (1,2-diarylhydrazines), benzidines, or amines. Whereas the reduction with zinc and sodium hydroxide leads to azo compounds, zinc and acetic acid/acetic anhydride produces azoxy compounds. Other reducing agents suggested are stannous chloride, magnesium with anhydrous methanol, a sodium-lead alloy in ethanol, thallium in ethanol, and sodium arsenite. 

According to E. Laurent,58 a soln. of sodium nitrate is decomposed in sunlight with the evolution of oxygen, while in darkness it is stable. Zinc dust reduces a soln. of potassium nitrate to the nitrite and hydroxide with the evolution of some oxygen above 60°, only a little nitrite but much nitrogen and ammonia are given off.59 The copper-zinc couple also reduces soln. of the nitrate, first to nitrite, and then to ammonia. Potassium amalgam, stannous chloride, etc., also reduce the nitrates in a similar way. 

Add a few drops of a solution of gold chloride (6 g. HAuC14-3H20 per liter) to about 5 cc. of water. To 50 cc. of water add one or two drops of a dilute solution of stannous chloride and one or two drops of a solution of sodium hydroxide. Add a little of this solution drop by drop, with constant stirring, to the solution of gold chloride. A deep rose-purple color, known as the purple of Cassius, slowly develops. It is due to finely divided gold. 

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