Chlorostannic acid, preparation

Preparation of Chlorostannic Acid. Pour concentrated hydrochloric acid into tin(IV) chloride in a proportion of 28 parts by mass of hydrogen choride to 100 parts by mass of the tin chloride. Cool the solution and pass a stream of dry hydrogen chloride into it until its absorption stops. Test the reaction of chlorostannic acid with... 

Chlorostannate ionic liquids have been used in hydroformylation reactions [23], Acidic [bmimjCl-SnCb and [l-butyl-4-methylpyridinium]Cl-SnCl2 were prepared from mixing the respective [cation]+ Cl with tin(II)chloride in a ratio of 100 104, much in the same way that the chloroaluminates are made (see Chapter 4). Both these chlorostannate ionic liquids melt below 25 °C. Addition of Pd(PPh3)2Cl2 to these chlorostannate ionic liquids leads to a reaction medium that catalyses the hydroformylation of alkenes such as methyl-3-pentenoate as shown in Scheme 8.9. The ionic liquid-palladium catalyst solution is more effective than the corresponding homogeneous dichloromethane-palladium catalyst solution. The product was readily separated from the ionic liquid by distillation under vacuum. This is an important reaction as it provides a clean route to adipic acid. 

Preparation of Ammonium Chlorostannate. Prepare a 60% tin(IV) chloride solution in concentrated hydrochloric acid and add to it a warm saturated solution containing an equimolecular amount of ammonium chloride. Cool the solution with a mixture of ice and sodium chloride, filter off the crystalline precipitate using a glass filter No. 3, and wash the precipitate on the filter with the smallest possible amount of concentrated hydrochloric acid cooled to 0 °C. 

The pivaloyl cation that can be formed from Me3CCl, AICI3, and CO at high pressure undergoes decarbonylation at normal pressure when it is prepared from pivaloyl chloride and most Lewis acids. Only in the presence of SnCU can one diacylate isobutene (from Me3CCl) with pivaloyl chloride to form 3 as chlorostannate, which can then be converted into other salts on... 

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