SnCl

It is prepared commercially by treating benzene diazonium chloride with sodium sulphite and then reducing the mixture with zinc dust and ethanoic acid. It can also be prepared by reduction of benzene diazonium chloride with SnCl. ... 

Tin IV) chloride, SnCU, stannic chloride. M.p. — 33" C, b.p. 1I4°C. Colourless fuming liquid (Sn plus CI2) hydrolysed in water but forms SnCl4,5H20 and [SnCl p" from acid solutions, soluble in organic solvents. Used as a mordant. 

Metals in higher oxidation states form halides which are essentially covalent, for example AICI3, SnCl, FeClj when these compounds dissolve in water they do so by a strongly exothermic process. Indeed it is perhaps incorrect to think of this only as a dissolution process, since it is more like a chemical reaction—but to differentiate for a particular substance is not easy, as we shall see. The steps involved in the case of aluminium chloride can be represented as... 

Obviously sufficient energy is available to break the A1—Cl covalent bonds and to remove three electrons from the aluminium atom. Most of this energy comes from the very high hydration enthalpy of the AP (g) ion (p. 78). Indeed it is the very high hydration energy of the highly charged cation which is responsible for the reaction of other essentially covalent chlorides with water (for example. SnCl ). 

This reaction proceeds slowly in aqueous solution, so that the basic salt. Sn(OH)Cl, is slowly precipitated. Addition of excess hydrochloric acid gives the acids of formulae HSnCl3 and H2SnCl4. Salts of these acids containing the ions SnCl J and SnCl (chloro-stannates(II)) are known. 

Both aliphatic and aromatic nitro-compounds can be readily reduced in acid solution to the corresponding primary amine. Thus when a mixture of nitrobenzene and tin is treated with hydrochloric acid, the tin dissolves to give stannous chloride, SnCh, which in these circumstances then reacts with more acid to give stannic chloride, SnCl, and the nascent hydrogen produced from... 

HjSnCl, with which the aniline forms a salt, aniline chlorostannate (C4HjNH )i,H SnCl4, similar in type to aniline chloroplatinate (p. 448). The crude product is therefore made strongly alkaline with sodium hydroxide, which liberates the base with the formation of sodium stannate, and the aniline can (C4H NH,),H,SnCl, + SNaOH = 2C,H,NH, + Na.SnO, +6NaCl + sHjO then be removed by steam-distillation. 

From nitriles by treatment with anhydrous Stannous chloride dissolved in ether saturated with hydrogen chloride the resulting crystaUine aldimine stannichloride, [(RCH=NHj)2] SnCl, or (RCH=NH,HCl)2SnCl4, is hydrolysed by warm water, and the aldehyde is isolated by distillation with steam or by extraction with a solvent (Stephen reaction), for example, for R = CH3(CH2)4, i.e., n-amyl ... 

Tertiary, benzyl, and aHyhc nitro compounds can also be used as Friedel-Crafts alkylating agents eg, reaction of (CH2)3CN02 (2-nitro-2-methyl propane [594-70-7]) with anisole in the presence of SnCl gives 4-/-butylanisole [5396-38-3] (7). SoHd acids, such as perfluorodecanesulfonic acid [335-77-3], and perfluorooctanesulfonic acid [1763-23-1] have been used as catalysts for regio-selective alkylations (8). 

Synthetic utility of stereoselective alkylations in natural product chemistry is exemplified by the preparation of optically active 2-arylglycine esters (38). Chirally specific a-amino acids with methoxyaryl groups attached to the a-carbon were prepared by reaction of the dimethyl ether of a chiral bis-lactam derivative with methoxy arenes. Using SnCl as the Lewis acid, enantioselectivities ranging from 65 to 95% were obtained. 

Acidic hahde catalysts used in chloromethylation include (44) ZnCl, ZnCl2 + AlCl, SnCl, SnCl, AlCl +ketones, AlCl + pyridine, AlCl ... 

Tertiary alkyl chlorides have been converted to the tertiary nittiles with trimethylsilyl nittile ia dichioromethane ia the presence of SnCl (131). The reaction was appHed to the synthesis of several bridgehead nittiles, such as 1-adamantyl and 1-diamantyl nittiles from the corresponding chloro or bromo derivatives usiag SnCl or AIBr. catalysts (132). 

C weak, low yields without side reactions BCl, BBr, BI, SnCl, TiCl, TiBr, ReCl, FeCl2, and PtCl ... 

BeCl2, CdCl, ZnCl2, BF, BCl, BBr, GaCl, GaBr, TiCl, ZrCl, SnCl, SnBr, SbCl, SbCl, BiCl, FeCl, and UCl. ... 

G-5 Aliphatic Petroleum Resins. Carbocationic polymerization of C-5 feedstreams has been accomptished with various Friedel-Crafts catalyst systems. Table 3 compares the efficiencies of selected Lewis acids ia the polymerization of a typical C-5 stream containing 43 wt % C-5—C-6 diolefias and 47 wt % C-5—C-6 olefins (20). Based on weight percent yield of resia at equimolar coaceatratioas of catalyst (5.62 mmol/100 g), efficieacy follows AICI3 AlBr3 > BF3etherate-H20 > TiCfy > SnCl. The most commonly used catalyst in petroleum resin synthesis is AlCl. ... 

Parameter AICI3 AlBt3 BF3 BF3 etherate/H20 TiCl SnCl AICI3/HCI ddb"... 

Catalysts used in the polymerization of C-5 diolefins and olefins, and monovinyl aromatic monomers, foUow closely with the systems used in the synthesis of aHphatic resins. Typical catalyst systems are AlCl, AIBr., AlCl —HCl—o-xylene complexes and sludges obtained from the Friedel-Crafts alkylation of benzene. Boron trifluoride and its complexes, as weU as TiCl and SnCl, have been found to result in lower yields and higher oligomer content in C-5 and aromatic modified C-5 polymerizations. 

In the synthesis of AGE with an acid as the catalyst, aHyl alcohol is added to the epoxy group of epichlorohydrin, yielding 3-aHyloxy-l-chloro-2-propanol [4638-03-3], which then undergoes cyclization with alkaU to yield AGE. Catalysts such as H2SO4, SnCl, BE (C2H )20 (33), heteropolyacids, HQO, andy -CH CgH SO H (34) are used. 

All lation. Thiophenes can be alkylated in the 2-position using alkyl halides, alcohols, and olefins. Choice of catalyst is important the weaker Friedel-Crafts catalysts, eg, ZnCl2 and SnCl, are preferred. It is often preferable to use the more readily accompHshed acylation reactions of thiophene to give the required alkyl derivatives on reduction. Alternatively, metalation or Grignard reactions, on halothiophenes or halomethylthiophenes, can be utilized. 

Acylation. To achieve acylation of thiophenes, acid anhydrides with phosphoric acid, iodine, or other catalysts have been widely used. Acid chlorides with AlCl, SnCl, ZnCl2, and BF also give 2-thienylketones. AH reactions give between 0.5 and 2.0% of the 3-isomer. There has been much striving to find catalyst systems that minimize the 3-isomer content attempting to meet to customer specifications. The standard procedure for formylation is via the Vil smeier-H a ack reaction, using phosphoms o xycbl o ri de / /V, / V- dim e tb yl fo rm a m i de (POCl /DMF) or /V-m ethyl form an i1 i de. 

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. 

R4S11 + S11CI4 2 R2S11CI2 R2S11CI2 + H4S11 2 RgSnCl 3 R Sn + SnCL... 

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