Stannic bromide, reaction

The gas or liq may attack organic matter with expl violence (Ref 11). Instances of violent reactions with ammonia, sulfur trioxide, stannic bromide and iodide are documented (Ref 12)... 

An analogous cation has been isolated for the diarsine derivative, namely [W(CO)4(diars)I]+ (181). The reaction of stannic bromide with Mo(CO)4 (diars) [and W(CO)4(diars)] appears to proceed in a similar way, so that an unstable mixed metal cation [Mo(CO)4(diars)SnBr3]+Br3 is produced, which decomposes to (diars)Mo(CO)2Br3 (179). 

There are two series of compounds of tin and the halogens those related to stannous oxide, SnO, in which the metal has a valence of 2 (stannous salts), and those related to stannic oxide, Sn02, in which it has a valence of 4 (stannic salts). The compounds with lower valence are usually prepared by the action of the halogen acids on the metal. Stannous chloride, for example, is formed when hydrochloric acid reacts with tin. Stannic salts, on the other hand, are prepared by the reaction of tin and the free halogen. In this preparation stannic bromide results from the reaction of bromine and tin. The reaction between the two ele-... 

Hydrogen haHde addition to vinyl chloride in general yields the 1,1-adduct (50—52). The reactions of HCl and hydrogen iodide [10034-85-2], HI, with vinyl chloride proceed by an ionic mechanism, while the addition of hydrogen bromide [10035-10-6], HBr, involves a chain reaction in which a bromine atom [10097-32-2] is the chain carrier (52). In the absence of a transition-metal catalyst or antioxidants, HBr forms the 1,2-adduct with vinyl chloride (52). HF reacts with vinyl chloride in the presence of stannic chloride [7646-78-8], SnCl, to form 1,1-difluoroethane [75-37-6] (53). 

A ubiquitous co-catalyst is water. This can be effective in extremely small quantities, as was first shown by Evans and Meadows [18] for the polymerisation of isobutene by boron fluoride at low temperatures, although they could give no quantitative estimate of the amount of water required to co-catalyse this reaction. Later [11, 13] it was shown that in methylene dichloride solution at temperatures below about -60° a few micromoles of water are sufficient to polymerise completely some decimoles of isobutene in the presence of millimolar quantities of titanium tetrachloride. With stannic chloride at -78° the maximum reaction rate is obtained with quantities of water equivalent to that of stannic chloride [31]. As far as aluminium chloride is concerned, there is no rigorous proof that it does require a co-catalyst in order to polymerise isobutene. However, the need for a co-catalyst in isomerisations and alkylations catalysed by aluminium bromide (which is more active than the chloride) has been proved [34-37], so that there is little doubt that even the polymerisations carried out by Kennedy and Thomas with aluminium chloride (see Section 5, iii, (a)) under fairly rigorous conditions depended critically on the presence of a co-catalyst - though whether this was water, or hydrogen chloride, or some other substance, cannot be decided at present. 

Recently, Mazzocchin et al. have studied several titration methods for determining relatively large amounts of technetium. The most precise results have been obtained by coulometric titration of TcO ions With electrogenerated tin (II) according to the procedure suggested by Bard and Lingaiie . The supporting electrolyte consists of 2.5 M sodium bromide, 0.15 M stannic chloride and 0.2 M hydrochloric acid. The titration reaction is very fast and currents up to 40 mA can readily be employed in the detection of the equivalence point. 

The catalytic activity of certain of the Friedel-Crafts catalysts was shown to decrease over a very wide range in the series boron fluoride, aluminum bromide, titanium tetrachloride, titanium tetrabromide, boron chloride, boron bromide and stannic chloride (Fairbrother and Seymour, mentioned in Plesch al., 83). When boron fluoride is added to isobutylene at dry ice temperatures, the olefin is converted to a solid polymer within a very few seconds. The time required for complete polymerization with aluminum bromide hardly extends to a few minutes while reaction times of hours are required with titanium chloride and periods of days with stannic chloride. 

A recent halogen-free benzofuran that shares many structural features with its predecessor shows activity in controlling arrythmias. The synthesis starts with an unusual scheme for building the furan ring. Reaction of the benzyl bromide (2-1) with triphenylphosphine leads to phosphonium salt (2-2). Treatment of the salt with valeryl chloride in the presence of pyridine results in acylation on the now highly activated benzylic carbon (2-3). That product cyclizes to the benzofuran (2-4) on heating with expulsion of triphenylphosphine. Friedel-Crafts acylation of (2-4) with anisoyl chloride in the presence of stannic chloride proceeds on the... 

Zinc chloride is much less reactive than aluminum chloride and usually requires higher reaction temperatures. However, it has the advantage that, unlike aluminum chloride, it is less sensitive to moisture and can sometimes even be used in aqueous media.88 Concentrated aqueous solutions of ferric chloride, bismuth chloride, zinc bromide, stannous chloride, stannic chloride, and antimony chloride are also alkylation catalysts, particularly in the presence of hydrochloric acid.89... 

Concentrated hydrochloric acid also dissolves the trichloride, about 100 g. of the latter dissolving in 1 litre of acid at 100° C.7 Dissolution in hydriodic acid is accompanied by evolution of heat and the triiodide is formed.8 Ethyl iodide reacts similarly.9 Double decomposition reactions occur w hen arsenic trichloride is heated with phosphorus triiodide, stannic iodide or germanium iodide, the reactions being complete.10 Similarly, potassium iodide heated with arsenic trichloride in a sealed tube at 210° C., and potassium bromide at 180° to 200° C., form respectively arsenic triiodide and tribromide.11 Stannous chloride, added to the solution in hydrochloric acid, causes reduction to arsenic (see p. 29). Arsenic trichloride may be completely separated from germanium chloride by extraction with concentrated hydrochloric acid.12 Ammonium, sodium and cobaltic chlorides react with arsenic trichloride to form additive compounds with magnesium, zinc and chromic chlorides there is no reaction.13... 

Detailed studies of systems involving aluminium-based Lewis acids and hydrogen halides are scarce. Fontana and Kidder investigated the polymerisation of propene initiated by the pair aluminium bromideTiydrt n bromide. The cocatalytic role of the latter acid was clearly proved since no polymerisation could be detected in its absence. The dependence of the rate of polymerisation upon the cocatalyst concentration and the induction periods observed make this system similar to those in which stannic chloride induces the polymerisation of olefins in the presence of variable quantities of water (see Sect. IV-C-3-b). With relatively large quantities of added hydrogen bromide, addition of this acid to the mcmomer to give fso-propyl bromide must have constituted an important side reaction. 

Preferably the reaction in accordance with the invention is performed in the presence of a suitable catalyst, proton acids such as for instance haloid acids, sulfuric acid, phosphoric acid, perchloric acid, organic sulfonic acids, such as for instance methanesulfonic acid and p-toluenesulfonic acid, carboxylic acids, such as for instance oxalic acid, trifluoroacetic acid and other Lewis acids, such for instance boron trifluoride, ferric chloride, zinc chloride, zinc bromide, stannic chloride, titanium chloride or iodine having proved to be suitable. Furthermore mixtures of the individual catalysts may be used in certain cases. 

When sodium vapour reacts with stannic chloride, bromide or iodide [89], a continuous chemOuminescence, which is emitted during the primary reaction, occurs. It was pointed out that neither Class I nor Class II mechanisms were applicable. The explanation suggested [55, 89] is the formation of SnCls radicals followed by a luminescent disproportionation reaction, the luminescence being associated with an electronic transition from the Sn" CI2 passing to the stable Sn Cl2 state... 

In further reactions of N-phenylbenzimidoyl chloride (56), methyl isothiocyanate and stannic chloride, in nitrobenzene at 110°C, gave 2-phenyl-4-methylthioquinazoline in moderate yield JV-phenyltrichloroacetimidoyl chloride reacted similarly.41 Then, in one of the few reactions that produce a halogenated pyrimidine ring, the chloride (56) with cyanogen bromide and stannic chloride (in nitrobenzene at 150°C) gave 4-bromo-2-phenylquinazo-line in excellent yield.41... 

Halomethylation of arenes. Arenes, under catalysis with stannic chloride or zinc bromide, undergo a Friedel-Crafts reaction with these reagents to give halomethylarenes. 

Direct glycosylation of 3-amino-5(7)/7-[l,2,4]triazolo[4,3-ft][l,2,4]triazole (17) with 1-D-acetyl-2,3,5-tri-(7-benzoyl-D-ribofuranose (18) in the presence of trimethylsilyl triflate gives the 1-(2,3,5-tri-0-benzoyl-) -D-ribofuranosyl) derivative (20). The same product (20) results from the high temperature glycosylation with boron trifluoride etherate in nitromethane as well as from the reaction of the triazolotriazole sodium salt with 2,3,5-tri-(7-benzoyl-D-ribofuranosyl bromide (19) (Equation (1)) <87Mi 80i-0l>, When 3-amino-5(7)/7-[l,2,4]triazolo[4,3-6][l,2,4]triazole (17) is treated with l-0-acetyl-2,3,5-tri-0-benzoyl-D-ribofuranose (19) and stannic chloride a mixture of four products is obtained. In addition to (20), the l-(2,3,5-tri-f -benzoyl-a-D-ribofuranosyl) derivative (21), the 3-imino-2,3-dihydro-7//-2-(2,3,5-tri-0-benzoyl-/ -D-ribofuranosyl) derivative (22), and the 3-(2,3,5-tri-0-benzoyl-)S-D-ribofuranosylamino) derivative (23) are isolated (Equation (1)) <93JHC1289>. 

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