Thionyl chloride, chlorination

Dangerous materials may require special equipment. Chlorination with gaseous chlorine requires quite expensive storage facilities. Chlorination with chlorine, thionyl chloride, sulphuryl chloride, phosphorus oxychloride, phosphorus trichloride, or phosphorus pentachloride, all of which are fairly hazardous, requires off-gas treatment. Some of these reactants can be recycled. Pyrophoric solids such as hydrogenation catalysts, anhydrous aluminium trichloride for Friedel-Crafts reactions, or hydrides used as reducing agents should usually be handled using special facilities. Therefore, all of the above proce.sses are usually carried out in dedicated plants. 

Improved versions of OLGA (versions II and III) enabled the applications of corrosive gases such as hydrogen chloride or hydrogen bromide, chlorine, thionyl chloride or boron tribromide vapor etc. This made it possible to synthesize volatile halides and measure their retention times in isothermal quartz columns. 

Phenoxatellurin 10,10-dihalides exchanged halogens upon treatment with chlorine, thionyl chloride, bromine, phosphorus tribromide, potassium bromide, or potassium iodide9. 

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. 

Introduction of Chlorine. Thionyl chloride is used to introduce chlorine in place of various groups, OH, SH, NO2, SO3H, hydrogen and oxygen. 

Benzaldehyde Chlorine Thionyl chloride Sodium bicarbonate... 

Trityl Ethers. Treatment of sucrose with four molar equivalents of chlorotriphenylmethyl chloride (trityl chloride) in pyridine gives, after acetylation and chromatography, 6,1, 6 -tri-O-tritylsucrose [35674-14-7] and 6,6 -di-O-tritylsucrose [35674-15-8] in 50 and 30% yield, respectively (16). Conventional acetylation of 6,1, 6 -tri-O-tritylsucrose, followed by detritylation and concomitant C-4 to C-6 acetyl migration using aqueous acetic acid, yields a pentaacetate, which on chlorination using thionyl chloride in pyridine and deacetylation produces 4,l, 6 -trichloro-4,l, 6 -trideoxygalactosucrose [56038-13-2] (sucralose), alow calorie sweetener (17). 

An economic synthesis of (3) has been patented (74,91). The process iavolves (/) synthesis of sucrose 6-acetate by way of sucrose 4,6-cychc orthoacetate (2), and (2) selective chlorination usiag thionyl chloride—pyridine—1,1,2-trichloroethane, followed by removal of the acetate group. 

Using sulfur trioxide plus chlorine, or sulfur dioxide plus chlorine, sulfur monochloride yields thionyl chloride [7719-09-7] SOCI2. Various nucleophilic reactions can displace the chlorine atoms of sulfur monochloride ... 

Physical Properties. Thionyl chloride [7719-09-7], SOCI2, is a colorless fuming Hquid with a choking odor. Selected physical and thermodynamic properties are Hsted in Table 6. Thionyl chloride is miscible with many organic solvents including chlorinated hydrocarbons and aromatic hydrocarbons. It reacts quickly with water to form HCl and SO2. Thionyl chloride is stable at room temperature however, slight decomposition occurs just... 

When the batch is completed, a slight excess of oleum and chlorine is added to reduce to a minimum the residual SCI2. Because thionyl chloride combines readily with sulfur trioxide to form the relatively stable pyrosulfuryl chloride, it is necessary to maintain the concentration of sulfur trioxide in the reaction mass at a low level hence, the addition of oleum to sulfur chloride rather than the reverse. When all of the reactants are added, heat is appHed to the jacket of the reactor and the batch is refluxed until most of the sulfur dioxide, hydrogen chloride, and chlorine are eliminated. The thionyl chloride is then distilled from the reactor. 

At present, thionyl chloride is produced commercially by the continuous reaction of sulfur dioxide (or sulfur trioxide) with sulfur monochloride (or sulfur dichloride) mixed with excess chlorine. The reaction is conducted in the gaseous phase at elevated temperature over activated carbon (178). Unreacted sulfur dioxide is mixed with the stoichiometric amount of chlorine and allowed to react at low temperature over activated carbon to form sulfuryl chloride, which is fed back to the main thionyl chloride reactor. 

The reactive intermediate, (C2H3)2NCH2CH2C1 HCl, which is used to produce cationic starch, is made by the reaction of (C2H3)2NCH2CH20H with thionyl chloride. A synthetic sweetener (qv), sucralose [56038-13-2] is made by the reaction of sucrose or an acetate thereof with thionyl chloride to replace three hydroxy groups by chlorines (187,188). 

Thallium (ITT) fluoride has been prepared by the action of fluorine or bromine trifluoride on thaUium(III) oxide at 300°C. It is stable to ca 500°C but is extremely sensitive to moisture. Thallium (ITT) chloride can be obtained readily as the tetrahydrate [13453-33-3] by passing chlorine through a boiling suspension of HCl in water. It can be dehydrated with thionyl chloride. Thallium (ITT) bromide tetrahydrate [13453-29-7] is prepared similarly, whereas the iodide prepared in this manner is thaUium(I) triiodide [13453-37-7] H" F2-... 

Treatment of coal with chlorine or bromine results in addition and substitution reactions. At temperatures up to 600°C chlorinolysis produces carbon tetrachloride, phosgene, and thionyl chloride (73). Treatment with fluorine or chlorine trifluoride at atmospheric pressure and 300°C can produce large yields of Hquid products. 

The first large-scale use of chlorine was for bleaching paper and cotton textiles it also is widely used as a germicide for public water supplies. Presently it is used principally in production of the chemical compounds sulfur chloride, thionyl chloride, phosgene, aluminum chloride, iron(ni) chloride, titaniura(IV) chloride, tin(IV) chloride, and potassium chlorate. 

Cholesterol, glycyrrhetic acid acetate Apply sample solution and moisten with anhydrous benzene, subject for 4 h to the vapors of thionyl chloride — benzene (1 -I-1) in a desiccator, then dry and develop. A chlorinated cholesterol or the chloride of 3- -acetoxyglycyrrhetic acid are formed. [16]... 

Treatment of valeroidine hydrobromide with thionyl chloride in an attempt to replaee the hydroxyl group by chlorine resulted in demethylation with the formation of norvaleroidine, a syrup yielding a crystalline hydrobromide, C12H21O3N. HBr, m.p. 270°, -)- 1° (c = 20 ... 

Condensation of normeperidine (81) with 3-chloropropan-l-ol affords the compound possessing the alcohol side chain (88). The hydroxyl is then converted to chlorine by means of thionyl chloride (89) displacement of the halogen by aniline yields pimino-dine (90). ° Condensation of the secondary amine, 81, with styrene oxide affords the alcohol, 91 removal of the benzyllic hydroxyl group by hydrogenolysis leads to pheneridlne (92). ... 

Further, d-citronellal, the corresponding aldehyde, may be converted into citronellic acid through its oxime and nitrile. Citronellic acid, when treated with thionyl chloride in benzene solution, yields a chloride of a chlorinated acid which is converted by the action of alcohol into the hydrochloride of ethyl citronellate, or hydrochloride of ethyl rhodinate,... 

Nitric add Dimethyl sulfate Thionyl chloride Hydrogen Chlorine... 

Treatment of phthalocyaninesulfonic or -carboxylic acids with chlorinating agents such as phosphorus pentachloride or thionyl chloride leads to the corresponding acid chlorides, e.g. 7. 

Tetrahydroimidazo[5,l-c][l,2,4]triazine 474 was prepared (79KGS1540) by treating imidazole derivatives 472 or 473 with hydrazine. Compound 473 was obtained by reaction of the respective imidazole with 1,2-dibromoethane or by the reaction of the alcohol derivative 471 with phosphorus tribromide. On the other hand, chlorination of471 with thionyl chloride gave 472 (Scheme 100). 

Polychlorination processes have included exhaustive chlorination in the presence of antimony pentachloride, which destroyed the molecule (1882JCS412). Chlorine in carbon tetrachloride gave 3,4,6,8-tetrachlo-roquinoline chlorine dissolved in thionyl chloride gave the 4,5,7,8-isomer, whereas thionyl chloride alone produced a mixture of 3,4,5,6,7,8-hexachloro- (57%) and 3,4,6,8-tetrachloro- (37%) quinolines (73YZ73 74S356, 74URP432143). 

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