Thionyl chloride, as solvent

Chloro(carbonyl)gold(I), [AuCl(CO)], is prepared in quantitative yield by the reaction of anhydrous AU2CI6 with CO at atmosphere pressme (equation 2). " With insufficient carbon monoxide, AU4CI8 is the product (equations). Anhydrous AU2CI6 is itself prepared in situ by dehydration of H[AuCLi]-3H20 with thionyl chloride as solvent (equation 4). 

Another example of a-halogenation which has synthetic utility is the a-halogenation of acyl chlorides. The mechanism is presumed to be similar to that of ketone halogenation and to proceed through an enol. The reaction can be effected in thionyl chloride as solvent to give a-chloro, a-bromo, or a-iodo acyl chlorides using, respectively, iV-chlorosuccini-... 

Poliak et al. claimed that the reaction of biphenyl 32 with excess chlorosulfonic acid (six equivalents) at 18 °C affords dibenzothiophene-5,5-dioxide-3,7-disulfonyl chloride 34, but more recent attempts to reproduce this result were unsuccessful and only the 4,4 -disulfonyl chloride 33 (80%) was isolated. However, the cyclized product 34 was obtained in good yield (72%) when biphenyl 32 was heated with a large excess of chlorosulfonic acid (20 equivalents) at 150 °C (4 hours) (Equation 11). The reaction presumably involves the formation of the intermediate biphenyl-2,4,4 -trisulfonyl chloride, 35 which subsequently cyclizes with loss of hydrogen chloride to give the dibenzothiophene dioxide 34. Further study of the action of chlorosulfonic acid on biphenyl 32 showed that the optimum yield of the 4-sulfonyl chloride (43%) was derived from treatment of 32 with the reagent (1.5 equivalents) in thionyl chloride as solvent at 0 °C (1 week). The best yield (89%) of the 4,4 -disulfonyl chloride 33 was also achieved by treatment of the hydrocarbon 32 with chlorosulfonic acid (three equivalents) in thionyl chloride at room temperature (1 week). 

The cis-fagaramide (J) was synthesized as outlined below. The required acetylenic acid (c) was prepared from piperonal (a) by the Corey s procedure.Treatment of piperonal with carbon tetrabromide, triphenylphosphine and zinc gave the bromo olefin (b) as an oil in 71% yield. The bromo olefin (b) was treated with 2 equivalents of n-butyl lithium followed by quenching with dry ice to give acetylenic acid (c) in 54% yield. Treatment of (c) with excess thionyl chloride without solvent at 50 followed by addition of isobutyl amine in benzene gave the acetylenic amide (d) as a viscous oil in 96% yield. Partial reduction of (d) gave cis-fagarmide (7 ) in 89% yield. 

PFAS can be supported on silica using a dehydrating solvent, obtaining an active catalyst. Spectroscopic studies suggest that the interaction between PFAS and the support is covalent. PFAS-Si02 catalyses the alkylation of isobutane with n-butenes to yield a mixture of products, of which saturated octanes are the major fraction. Trimethylpentanes are the main constituent of this fraction. The best results were obtained using thionyl chloride as the dehydrating solvent. 

Very useful is 4-pyridylpyridinium chloride-hydrochloride (65), which is obtained by reaction of pyridine 64 with thionyl chloride as described in Section IV,B. 4-Pyridylpyridinium chloride-hydrochloride (65), which can be readily prepared in large quantities, reacts on heating in DMFas solvent and reactant (cf. Section 1II,B and especially IV,B reactions 105-108) to form the important nucleophilic catalyst DMAP (228) on a technical scale in —60-70% yield. Similarly, N-formy I pyrrolidine affords PPY (184) in 60% yield (77USP4I40853). 

Ekkati and Bates reacted more functionalized amides using 2,5-dimethoxytetrahydrofuran as the solvent and thionyl chloride as the acid source to generate a variety of iV-acyl pyrroles similar to 5 with good yields. Under these conditions the reaction times and temperatures were greatly reduced. 

In some cases, chlorosulfonation has been promoted by using a mixture of chlorosulfonic acid and thionyl chloride sometimes it was found preferable to react the substrate with chlorosulfonic acid alone first and then add the thionyl chloride later. " This modification allows the amount of chlorosulfonic acid to be reduced sometimes to just one molar equivalent, and may convert the intermediate sulfonic acid to the sulfonyl chloride where the conversion does not occur effectively in the absence of thionyl chloride. An example would be a substrate containing a substituent capable of hydrogen bonding with the sulfonic acid group, such as an ortho-hyamino group. The use of sulfuryl chloride, instead of thionyl chloride, as a chlorinating solvent was not successful because it... 

A simpler nonphosgene process for the manufacture of isocyanates consists of the reaction of amines with carbon dioxide in the presence of an aprotic organic solvent and a nitrogeneous base. The corresponding ammonium carbamate is treated with a dehydrating agent. This concept has been apphed to the synthesis of aromatic and aUphatic isocyanates. The process rehes on the facile formation of amine—carbon dioxide salts using acid haUdes such as phosphoryl chloride [10025-87-3] and thionyl chloride [7719-09-7] (30). 

The a -halosulfone, required for the Ramberg-Backlund reaction, can for example be prepared from a sulfide by reaction with thionyl chloride (or with N-chlorosuccinimide) to give an a-chlorosulfide, followed by oxidation to the sulfone—e.g. using m-chloroperbenzoic acid. As base for the Ramberg-Backlund reaction have been used alkoxides—e.g. potassium t-butoxide in an etheral solvent, as well as aqueous alkali hydroxide. In the latter case the use of a phase-transfer catalyst may be of advantage. ... 

The first step involves the preparation of 1 -(3-isobutoxy-2-chloro)propyl pyrrolidine as an intermediate. 345 ml of thionyl chloride dissolved in 345 ml of chloroform are added, drop by drop, to 275 g of 1 -(3-isobutoxy-2-hydroxy)propyl pyrrolidine dissolved in 350 ml of chloroform, while maintaining the temperature at approximately 45°C. The reaction mixture is heated to reflux until gas is no longer evolved. The chloroform and the excess of thionyl chloride are removed under reduced pressure. The residue is poured on to 400 g of crushed ice. The reaction mixture is rendered alkaline with soda and the resulting mixture is extracted twice with 250 ml of diethyl ether. The combined ethereal extracts are dried over anhydrous sodium sulfate. After evaporation of the solvent the residue is distilled under reduced pressure. 220 g of product are obtained having the following properties boiling point = 96°C/3 mm, n074 = 1.4575. 

The flask is removed from the oil bath and cooled to room temperature. To the reaction mixture are added successively 21.4 g. (0.12 mole) of finely powdered Nduomosuccininiide (l-bromo-2,5-pyrrolidinedione) (Note 4), 50 ml. of carbon tetrachloride, and 7 drops of aqueous 48% hydrogen bromide (Note 5). The flask is heated at 70 for 10 minutes (Note 6), and the temperature of the bath is then increased to 85° until the color of the reaction becomes light yellow (ca. 1.5 hours Note 7). The reaction mixture is cooled to room temperature, and the carbon tetrachloride and excess thionyl chloride are removed under reduced pressure (Note 8). The residue is suction filtered, and the solid (Note 9) is washed several times with carbon tetrachloride (total 20 ml.) and the combined filtrate collected in a 50-rnl. flask. The solvent is removed from the solution as before, and the residue is distilled into a dry ice-cooled receiver (short-path column) to give, after a small forerun, 16.1-17.1 g. (76-80%) of 2-bromohexanoyl chloride, b.p. 44-47 (1.5 mm.) as a clear, slightly yellow oil, n12 d 1.4707. This material is of sufficient purity for most synthetic purposes (Note 10). 

Fisher Scientific Company (reagent-grade) or Matheson Coleman and Bell. The first two were slightly yellow, and the latter was colorless however, the yields of final product were identical with each brand. The excess thionyl chloride serves as a drying agent for the hexanoic acid and as a solvent for the IV-bromosuecinimide, which is not very soluble in carbon tetrachloride. 

In batteries of this type, solntions of lithium salts in thionyl chloride, SOCI2, are nsed as the electrolyte. Exceptionally, this strongly oxidizing solvent also serves as the active material for the cathodic reaction. Thus, during discharge thionyl chloride is electrochemicaUy reduced at a cathode made of carbon materials ... 

Apart from the work toward practical lithium batteries, two new areas of theoretical electrochemistry research were initiated in this context. The first is the mechanism of passivation of highly active metals (such as lithium) in solutions involving organic solvents and strong inorganic oxidizers (such as thionyl chloride). The creation of lithium power sources has only been possible because of the specific character of lithium passivation. The second area is the thermodynamics, mechanism, and kinetics of electrochemical incorporation (intercalation and deintercalation) of various ions into matrix structures of various solid compounds. In most lithium power sources, such processes occur at the positive electrode, but in some of them they occur at the negative electrode as well. 

Another general method for converting alcohols to halides involves reactions with halides of certain nonmetallic elements. Thionyl chloride, phosphorus trichloride, and phosphorus tribromide are the most common examples of this group of reagents. These reagents are suitable for alcohols that are neither acid sensitive nor prone to structural rearrangement. The reaction of alcohols with thionyl chloride initially results in the formation of a chlorosulfite ester. There are two mechanisms by which the chlorosulfite can be converted to a chloride. In aprotic nucleophilic solvents, such as dioxane, solvent participation can lead to overall retention of configuration.7... 

This modification of the continuous reactor (cf. benzoylacetanilide, p. 2) with countercurrent distillation is preferred for reactions in which a large amount of solvent or excess of one reactant is essential, but increase of total volume is undesirable. It is especially useful if the substances involved are heat-sensitive with this apparatus the reactants are heated for only a few minutes at most. It is particularly applicable to the preparation of acid chlorides from carboxylic acids and thionyl chloride (cf. Notes 3 and 4). An indefinite amount of product can be prepared by replenishing the reactants as they are consumed. 

---