A-Chlorinating reagent

The chloride of triflic acid (trifluoromethanesulfonyl chloride) is an effective sulfonylating agent Like triflic anhydride, it usually reacts with alcohols and other nucleophiles with the formation of the corresponding derivatives of tnflic acid [69] However, in some reactions, it acts as a chlorinating reagent [98] The reactions of tnfluoromethanesulfonyl chloride with 1,3-dicarbonyl compounds or some carboxylic esters in the presence of a base result m the formation of chlonnated products in high yields (equation 49)... 

Dialkyl and diaryl ditellurides are easily converted into the corresponding tellurium trichlorides by means of the fission of the Te-Te bond by a chlorinating reagent. This route is very suitable for the preparation of the alkyl derivatives in view of the easy accessibility of dialkyl ditellurides via the alkylation of sodium ditelluride (see Section 3.2.1). 

Bromofluorination of dodec-2-ene, styrene, and methyl undec-10-enoate are carried out using similar conditions but using l,3-dibromo-5,5-dimethylhydantoin instead of A-halosuc-cinimide however, chlorofluorination with A-chlorosuccinimide as a chlorinating reagent is not successful at all and starting alkenes are recovered unchanged.336... 

S02C12) acts as a chlorinating reagent. Here, the chlorination of tert-butylbenzene is shown. 

Trichloromedianesulfonyl chloride has also been used as a chlorination reagent for alkanes, but this reaction requires a peroxide initiation step (equation 80). ... 

Indok synthesis. Gassman and van Bergen have used a modification of the above-mentioned procedure for synthesis of 2-substituted indoles from anilines. The aniline IS treated as above with a chlorinating reagent at — 65° and then an equivalent of methyl-thio-2-propanone at the same temperature. An equivalent of a base (usually triethyl-amine) is added. Workup affords the indole derivative (2) in 60-70% yield. The thio-methyl group is removed with Raney nickel (>70% yield). The keto sulfide can be varied thus nse of methyl phenacyl sulfide [CH3SCH2C(=0)C5H5]4 in the synthesis leads to 2-phenylindoles. 

One interesting feature of this work is that the enzyme chlorinase also can chlorinate anisole in water solution, but it gives a random mixture of ortho and para products [65]. Apparently the enzyme merely makes a chlorinating reagent, probably HOCl, and this then acts on the unbound anisole in free solution. However, the selectivity seen in our anisole complex chlorination is typical of that seen in other enzymes that do indeed direct reactions by geometric control within an enzyme-substrate complex. 

A chlorination reagent can be prepared by the treatment of the hydrolodlde of poly(styrene-co-vlnylpyridine) with chlorine. Alternatively, the methylpyridinium iodide polymer can be used. 

It has been observed that no further chlorination occurs on Herz compounds in the presence of a chlorination reagent (e.g., SOCI2), thus the chlorination on aromatic nucleus probably occurs before the formation of the Herz compounds. A tentative mechanism is outlined here. 

This reaction has been modified by the in situ chlorination of sulfone using CCI4 as a chlorination reagent. In addition, the sulfones have been mixed with powdered KOH and AI2O3 to improve the extrusion of S02. The reaction is also extended to a solid-phase supported condition (e.g., resin). ... 

Also chlorination using sulfuryl chloride as a chlorination reagent is examined [131]. The Mikroglas Dwel Device (Foturan glass, 1000 [tm width, 500 (tm depth, and 1.9 m length, and total hold-up volume of 0.95 ml) was used as a micro reactor. 

Nitrobenzene (89, 184.5 g) by reaction with a mixture of iodine (1.1 g) and 98% sulfuric acid (57 g) in chlorosulfonic acid at 30 °C afforded pentachloroni-trobenzene 90 (87% yield) (Equation 28). The product is useful as a soil fungicide and the s)mthesis provides another example of the use of a mixture of chlorosulfonic acid and iodine as a chlorinating reagent (see Section 3, p 50). The rate of chlorination of nitrobenzene 89 to pentachloronitrobenzene 90 by the chlorosulfonic acid-iodine mixture increased with the iodine concentration. However, the rate was less than that observed in the presence of iodine chlorides. The most effective catalyst for chlorination was found to be a mixture of 0.75% iodine chlorides in chlorosulfonic acid which was stable for 3 days. ... 

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