Modification with sulfonyl chloride

Modification with Lissamine Rhodamine B Sulfonyl Chloride... 

Modification of (strept)avidin with Texas Red sulfonyl chloride may be done similarly, except the fluorophore is first dissolved in acetonitrile prior to addition to the aqueous reaction mixture. 

The reactions of the completely reduced compounds have attracted much attention because of their close relationship to piperazine. Thus it has been shown, as might be expected, that the 2-position in compounds such as the parent 100 can be readily acetylated and benzoylated" and ureas are formed with phenylisocyanate and phenylisothiocyanate." Compound 100 also reacts at the 2-position with p-acetamidobenzene-sulfonyl chloride to give a sulfonamide. There are several examples of the alkylation of the amine in the 2-position. Various alkyl halides -have been used, as well as ethylene oxide," p-nitrobenzoyl-ethyleneimine, " and l-guanyl-3,5-dimethylpyrazole nitrate. Compound 100 also undergoes the Eschweiler-Clarke modification of the Leuckart reaction to give the 2-methyl compound." ... 

A standard condition has been optimized for this reaction, in which the aryl amine is diazotized in 10 times its amount of acetic acid, followed by the addition of one equivalent of cuprous halide in hydrohalic acid. Under these conditions, the acetate salt of aryl amine is relatively soluble, and less froth and tarry material are formed during diazo transformation. In addition, chlorination, bromination, and iodonation of p-haloaniline to dihalobenzenes under such standard conditions give almost comparable average yields. Other modifications of this reaction include the formation of phenyl selenocyanate by the reaction with potassium selenocyanate, and aryl nitrile by the reaction with nickel cyanide. Moreover, this reaction has been extended to the preparation of phenyl thiocyanate, phenyl isothiocyanate and aromatic sulfonyl chloride. ... 

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... 

Chlorobenzene reacts with an equimolar amount of chlorosulfonic acid to give mainly the p-sulfonic acid together with a little of the sulfonyl chloride and the sulfone. With an excess of the reagent good yields of p-chlorobenzenesulfonyl chloride are obtained. The kinetics of the sulfonation of chlorobenzene with chlorosulfonic acid have been studied, and the reaction has been reported in several patents. These involved various modifications such as the use of excess reagent in hydrocarbon solvents containing alkali metal or ammonium salts, or a mixture of the reagent with thionyl chloride in the presence of sulfamic acid, sodium sulfate or dimethylformamide. In the reaction, the yield of 4,4 -dichlorodiphenyl sulfone can be increased under a variety of conditions the... 

---