in situ generation of HSO3Cl !

[psyloxy]

Patent DE385049

Example 2

70 parts finely ground NaCl are introduced to 300 parts 60% oleum. Then, whith cooling and under good stirring, 92 parts toluene are added. The whole is stirred for some hours and poured on ice, whereupon the mixture of isomeric tosylchlorides (140 parts) precipitates and is worked up as usual.

Would anyone object, that for alkylation purposes o-/p-TsOAlk are equally usable ?

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[psyloxy]

Patent DE98030

100kg toluene are slowly introduced to 400kg of chlorosulfonic acid, cooled to 0°C, with constant stirring, care being taken that the temperature doesn't exceed 5°C. After the toluene addition is complete, the mixture is stirred for 12h at 0-5°C. The mixture is then poured on ice, the toluenesulfochlorides form their own layer and are separated by decantation. After the TsCl-layer has been cooled to -20°C for 12h the p-TsCl crystallized and is removed from the o-TsCl by suctin filtration. Yield: 100%, ortho:para=60%:40%.

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[psyloxy]

Bull.Soc.Chim.Fr., 39,4.1926;316

Je ne parelé pas francaise ... but: Ph-SO₃Na + HSO₃Cl ^__> Ph-SO₂Cl in 65% - TsOH ^__> TsCl, same procedure, same yield.

J.Gen.Chem.USSR, 52,2.1982;341-343

non too informative article, but yields are given when only 1.2 equiv. of HSO₃Cl are used. Actual procedure is in a russian ref.

Chem.Ber., 12.1879;1849-1850

An old German article, only 50% yield. Rests here so nobody thinks there's better methods out there then presented in the patents above.

Just in case you didn't notice:

Post 514474

(psyloxy: "chlorosulphonic acid", Chemistry Discourse)

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