Anhydrous Stannic Chloride

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Write ionized equations for (a) the precipitation of basic stannous chloride SnOHCl, when a solution of SnCl2 is diluted with a large amount of water (6) the conversion of SnOHCl to SnS when this precipitate is treated with Na S solution. 

Apparatus 350-cc. tubulated retort or distilling flask, five 8-ounce wide-mouth bottles, chlorine generator (2,000-cc. flask) or cylinder of liquid chlorine. 

150-cc. container for stannic chloride the neck must be previously drawn out to a narrow tube that can be quickly sealed off in blast flame, delivery tubes, connectors, and rubber stoppers as in diagram, tripod. 

This preparation is to be attempted only if 4 consecutive hours are available in the laboratory, and even then, the apparatus should be assembled at a previous exercise. 

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Stannic Chloride. Stannic chloride is available commercially as anhydrous stannic chloride, SnCl (tin(IV) chloride) stannic chloride pentahydrate, SnCl 5H20 and in proprietary solutions for special appHcations. Anhydrous stannic chloride, a colorless Aiming Hquid, fumes only in moist air, with the subsequent hydrolysis producing finely divided hydrated tin oxide or basic chloride. It is soluble in water, carbon tetrachloride, benzene, toluene, kerosene, gasoline, methanol, and many other organic solvents. With water, it forms a number of hydrates, of which the most important is the pentahydrate. Although stannic chloride is an almost perfect electrical insulator, traces of water make it a weak conductor. 

A solution of anisole (10.8 g, 0.1 mol), phosphorus trichloride (41 g, 0.30 mol), and anhydrous stannic chloride (2 ml) was refluxed under dry nitrogen for 76 h. An additional 2 ml of stannic chloride was added every 12 h. At the end of this time, the reaction mixture was concentrated under reduced pressure, and the residue was vacuum distilled (74 to 78°C/0.05 torr) through a 10-in. Vigreux column to give pure 4-methoxyphenylphosphonous dichloride (19.8 g, 91%). 

Anhydrous sodium tungstate, 25 382 Anhydrous stannic chloride, 24 803 Anhydrous stannous chloride, 24 802-803 Anhydrous zinc chloride, 26 617 Anhydrous zinc sulfate, 26 617 Aniline, 2 783-809, 17 250, 259 alkylation, 2 197 Bechamp process, 2 490 from benzene, 3 619t, 620 chemical reactions, 2 783-789 derivatives, 2 783-809 economic aspects, 2 790-791... 

Dibenzothiophene has recently been synthesized from 2-allylbenzo-[fcjthiophene (24) by treatment with dichloromethyl butyl ether and anhydrous stannic chloride at low temperatures, as shown in Eq. (1) (55%). This sequence has been extended by the use of substituted allyl groups and modified formylating agents to yield dibenzothiophenes substituted in the 1-, 1,3-, and 3-positions. For example, treatment of 2-allylbenzo[6]thiophene with the modified formylating agent EtOCCl2-... 

Condensation of 3-chloromethylbenzo[6]thiophene with diethyl malonate followed by hydrolysis, decarboxylation, Arndt-Eistert homo-logization, hydrolysis, and cyclization of the derived acid chloride with anhydrous stannic chloride yielded 2-methyl-4-keto-l,2,3,4-tetrahy-drodibenzothiophene (47). ... 

A weighed quantity of anhydrous stannic chloride, SnCl4, is treated with six equivalents of water in the form of a concentrated solution of hydrochloric acid. The proportions required are 100 parts of SnCl4 and 41.64 parts of water, corresponding to 60.15 parts of 33 per cent hydrochloric acid of sp. gr. 1.166. 

To a vigorously stirred solution of 40.7 g 2,5-dimethoxyfluorobenzene in 215 mL CH,C12 cooled with an external ice bath, there was added 135 g of anhydrous stannic chloride. There was then added, dropwise, 26 g of dichloromethyl methyl ether at a rate that precluded excessive heating. The reaction mixture was allowed to come to room temperature over the course of 0.5 h, and then quenched by... 

One process from US Patent 4,107,162 27.4 g of 2,4-bis(trimethylsilyl)-5-fluorouracil and 7.7 g of 2,3-dihydrofuran are dissolved in 70 ml of acetonitrile, and 30 ml of an acetonitrile solution containing 1.3 g of anhydrous stannic chloride are added thereinto with cooling and stirring. 50 ml of acetonitrile containing 1.3 ml of water dissolved therein are then dropwise added over 15 minutes. After return to room temperature, the reaction is further effected with stirring at 40°C for 5 hours. The reaction mixture is neutralized by adding 1 N aqueous ammonia with cooling and... 

Direct rearrangement to cyclobutanones can be achieved under four sets of conditions a) with 48% aqueous fluoroboric acid in ether, at room temperature b) with anhydrous stannic chloride in methylene chloride, normally at room temperature c) with p-toluenesulfonic acid in benzene saturated with water, at reflux and d) with trimethyloxonium tetrafluoroborate in methylene chloride (Meerwein s reagent). For instance, the cyclopropylcarbinol 233 was rearranged to 2-/-butyl-2-methylcyclo-butanone 235, upon treatment with one equivalent of pTsOH in water-saturated benzene at reflux for 1.5 hr, Eq. (72) 139). In a slightly different approach, the alcohol... 

Caution This preparation should be carried out in a hood since 2-nitropropene is a powerful lacrimator and anhydrous stannic chloride is a skin irritant. 

A fresh bottle of commercial anhydrous stannic chloride purchased from Wako Pure Chemical Industries, Ltd., Japan, or from Fluka AG, Buchs, Switzerland, was used without purification. 

Reaction of 1-lithiocyclopropyl phenyl sulphide (123) with 4-t-butylcyclohexanone produces an adduct as a 99 1 mixture of two isomers. By analogy to organometallic addition to this ketone, the stereochemistry is assumed to result from equatorial attack. Treatment of the adduct with one equivalent of anhydrous stannic chloride followed by hydrolysis produces primarily cyclobutanones (equation 94) ... 

The title cyclobutanone has been prepared previously by the addition of (l-phenylthio)cyclopropyllithlum to crotonaldehyde followed by rearrangement with anhydrous stannic chloride in methylene chloride.However, in our experience, the procedure described here is much more convenient and reproducible on a large scale. 

Persoz, Deluyne, and Calvetet obtained (1861) a soluble blue dyestuff by the action of anhydrous stannic chloride on aniline (pure ). The composition of this compound is not known, neither has it been applied in practice [41]. 

A mixture of 153 mg (0.85 mmol) of olivetol, 132 mg (0.87 mmol) of (-i-)-cjs//rans-p-mentha-2,8-dien-l-ol and 200 mg of anhydrous magnesium sulfate in 5 mL of methylene chloride was stirred and cooled to ice bath temperature. Fifty microliters of anhydrous stannic chloride (0.111 g, 0.4 mmol) was added and stirring and cooling was continued. After 10 minutes, the reaction mixture was analyzed by gas-liquid chromatography and shown to contain 30 percent of (-)-6a,10a- rans-l-hydroxy-3-n-pentyl-6,6,9-trimethyl-6a,7,8,10a-tetrahydrodibenzo[b,d]pyran. After quenching the reaction with sodium carbonate, the desired compound can be isolated from the reaction mixture. 

Use Substitute for anhydrous stannic chloride where the presence of water is not objectionable. 

According to the procedures developed by Levine and Cass, cyclohexane admixed with about 3 per cent anhydrous stannic chloride is subjected to the action of dry chlorine in the absence of light. The chlorination is slow but smooth when the temperature is maintained at 40 C. A yield of 89 per cent monochlorocyclohexane and about 10 per cent dichloro-cyclohexanes is obtained when 38 per cent of the chlorine necessary for complete halogenation is used. When the reaction is carried out in the presence of light in a lead-lined vessel, the reaction is more rapid. A yield of 82.5 per cent monochlorocyclohexane is obtained when 63 per cent of the chlorine necessary for complete monochlorination is introduced. 

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