Thionyl chloride purification

The submitters used Matheson thionyl chloride without further purification. 

Materials and Purification. Chemicals were purchased from Aldrich chemical company and used as received unless otherwise noted 1,1,1,3,3,3-hexamethyl disilazane, ethylene glycol, triphosgene, poly(ethylene oxide) (MW = 600), poly(tetramethylene oxide) (MW = 1000), poly(caprolactonediol) (MW = 530), toluene diisocyanate (TDI), anhydrous ethanol (Barker Analyzed), L-lysine monohydride (Sigma) and methylene bis-4-phenyl isocyanate (MDI) (Kodak). Ethyl ether (Barker Analyzer), triethylamine and dimethyl acetamide were respectively dried with sodium, calcium hydride and barium oxide overnight, and then distilled. Thionyl chloride and diethylphosphite were distilled before use. 

Further routes of cyclizations have been studied in parallel in the case of cis- and rra/J5-2-hydroxymethyl-l-cyclohexylamine (106) (880PP73). The preparation of thiourea or urea adducts 107 and 108 with phenyl isothiocyanate or phenyl isocyanate proceeds smoothly. The reaction of 107 with methyl iodide and subsequent alkali treatment, by elimination of methyl mercaptan, resulted in the iminooxazine 109 in high yields. The ring closures of both cis and trans thiourea adducts to 1,3-oxazines proceed with retention. Cyclodesulfuration of the adduct 107 by mercury(II) oxide or N,N -dicyclohexylcarbodiimide resulted in the iminooxazine 109, but the yield was low and the purification of the product was cumbersome. The ring closure of 108 with thionyl chloride led to the iminooxazine 109 in only moderate yield. 

Eastman Kodak Company thionyl chloride (b.p. 75-76°) was used without further purification. 

The traditional methods utilize sulfur or phosphorous halides to convert the acid to die acid chloride. Of these methods, thionyl chloride [often with a catalytic amount of dimethyl formamide (DMF)] is the most useful since the by-products of die reaction are gases (SO2, HC1) which can be easily purged from the reaction mixture with a stream of nitrogen. The acid chloride product can then be purified on a small scale by bulb-to-bulb distillation or crystallization. Because an excess of thionyl chloride is usually used, there must be a purification step to remove the excess reagent. 

Treatment of p-acetoxybenzoic acid with thionyl chloride generated the acid chloride, which was used without purification to acylate diethyl L-glutamate. Deacetylation of the resulting triester (36) gave (37) [51] (Scheme 3.6). 

To a solution of 65.2 g of 2,6,2, 6 -tetramethylbenzylhydrol in 170 ml of anhydrous benzene and 33.0 g of dry magnesium sulfate 20 ml of freshly distilled thionyl chloride are added drop-wise with stirring. Stirring is continued for another hour after completion of the addition and, after filtration, the solvent is removed under reduced pressure. The 70.0 g of 2,6,2 6 -tetramethylbenzhydryl chloride, is obtained and then used without previous purification for the next reaction step. 

In a 500-cc. round-bottomed flask fitted with a reflux condenser carrying at the top a tube leading to a gas absorption trap (Org. Syn. 14, 2) are placed 32.8 g. (0.2 mole) of 7-phenyl-butyric acid (p. 64) and 20 cc. (32 g., 0.27 mole) of thiony] chloride (Note 1). The mixture is carefully heated on a steam bath until the acid is melted and then the reaction is allowed to proceed without the application of external heat. After twenty-five to thirty minutes hydrogen chloride is no longer evolved and the mixture is warmed on the steam bath for ten minutes. The flask is then connected to the water pump, evacuated, and heated for ten minutes on the steam bath and finally for two or three minutes over a small flame in order to remove the excess thionyl chloride. The acid chloride thus obtained is a nearly colorless liquid and needs no further purification. The flask is cooled, 175 cc. of carbon disulfide is added, and the solution cooled in an ice bath. Thirty grams (0.23 mole) of... 

Reduction (lithium aluminium hydride/tetrahydrofuran) of the tetraester 34 to the tetraol 35, followed by chlorination (thionyl chloride), afforded 36 in good yield. This tetrachloride was then subjected to base-promoted P-elimination (potassium rerf-butoxide) giving the desired bisdiene 37 in quantitative yield without purification. The sensitivity of 37 toward both thermal and photochemical degradation and its propensity to polymerize necessitated its immediate use following its preparation. 

The trichlorocyclotrithiazene is obtained11 by stirring tetrasulfur tetranitride or S3N2C12 with excess sulfuryl chloride (2-3 mL per gram of sulfur compound) for ca. 24 hr at room temperature, in a flask fitted with an exit bubbler. After excess solvent has been removed by distillation (at ca. 20° under reduced pressure) and the residue has been pumped dry, the (NSC1)3 is obtained as a pale-yellow powder. Further purification is usually unnecessary but if analyses or a darker color indicate that some decomposition has occurred (e.g., through exposure to atmospheric moisture), it can be recrystallized from thionyl chloride or sulfuryl chloride. To obtain a good recovery, the mixture should be filtered at ca. —10°. 

A mixture of 3-bromo-2-thienyl carboxylic acid (2.5 mmol) and 3 ml of thionyl chloride was refluxed 4 hours, then concentrated. The residue was co-evaporated twice with toluene, then extracted with 12.5 ml CH2C12, and treated with 3-methyl-butylamine (3 mmol) and triethylamine (5.5 mmol). The mixture was stirred overnight and was then washed with NaHC03 solution, dried, concentrated, and around 1.5-2.5 mmol product isolated and used without further purification. 

Thionyl chloride (3.16 mol) was added to a solution of yV- me th y 1 -4 - n itropyrro 1 e-2 -carboxylic acid (1.17 mol) dissolved in 1500 ml toluene, then stirred 3 hours at 100°C, and concentrated. A suspension formed which was stirred 2 hours with cyclohexane at ambient temperature. The mixture was then filtered, dried, and the product isolated in 96% yield. The product was used without further purification. 

The Step 3 product (0.45 mol) dissolved in 3 ml DMF was treated with thionyl chloride (2.3 mol) dissolved in 2500 ml CH2C12, then refluxed 6 hours, cooled, and filtered. The crude product was washed with 1000 ml hexane, filtered, dried, the product isolated in 90% yield. The material was used directly without further purification. 

The Step 4 product (0.4 mol) suspended in 1500 ml of toluene was treated with 35 ml thionyl chloride, then stirred 2 hours at 70°C, and further treated an additional 16 ml thionyl chloride until sulfur dioxide evolution stopped. The solution was concentrated and 139.5 g crude product isolated. The material was used without further purification. 

The Step 2 product (17.1 mmol) and thionyl chloride (0.277 mol) were refluxed 3 hours. Excess thionyl chloride was removed by distillation, and the crude product was isolated in 98% yield and used without additional purification. 

Derivative 13e, obtained as it is described in Scheme P, has been maken react with thionyl chloride in methylene chloride and in presence of triethylamine, so we have obtained cyclic sulphite 13n as a stable intermediate in 94% yield after chromatographic purification. 

Anhydrous lanthanide trihalides, particularly the trichlorides, are important reactants for the formation of a variety of lanthanide complexes, including organometallics. Routes for the syntheses of anhydrous lanthanide trihalides generally involve high temperature procedures or dehydration of the hydrated halides.The former are inconvenient and complex for small scale laboratory syntheses, while dehydration methods may also be complex and have limitations, for example, use of thionyl chloride. - Moreover, the products from these routes may require purification by vacuum sublimation at elevated temperatures. Redox transmetalation between lanthanide metals and mercury(II) halides was initially carried out at high temperatures. However, this reaction can be carried out in tetrahydrofuran (THF, solvent) to give complexes of lanthanide trihalides with the solvent. These products are equally as suitable as reactants for synthetic purposes as the uncomplexed... 

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