[98-68-0] · C7H7ClO3S · p-Anisolesulfonyl Chloride · (MW 206.65)
(versatile sulfonating agent; useful for the preparation of sulfonamides or as an N-protecting group2)
Alternate Name: 4-methoxybenzenesulfonyl chloride.
Physical Data: mp 40-43 °C.
Solubility: sol acetone, acetonitrile, EtOH, MeOH, dioxane, H2O.
Form Supplied in: solid; widely available 98% pure.
Handling, Storage, and Precautions: corrosive and a lachrymator. Store at room temperature under anhydrous conditions. Use in a fume hood.
4-Methoxybenzenesulfonyl chloride has been employed in the preparation of a wide variety of sulfonamides leading to a number of biologically active compounds.3,4 The nonprostanoid thromboxane (TXA2) receptor antagonist (2) was prepared from the primary amine in the presence of 4-methoxybenzenesulfonyl chloride (1) (1.2 equiv) and excess Triethylamine (eq 1).3 Arenesulfonyl chlorides have also been used for the synthesis of sulfonyl cyanides5 and arylthiocyanates.6
The addition of sulfonyl chlorides to alkenes in the presence of a catalytic amount of Dichlorotris(triphenylphosphine)ruthenium(II) affords 1:1 adducts.7 Under these reaction conditions it is believed that sulfonyl radicals, which are confined to the coordination sphere of the metal complex, are involved. When the chiral phosphine (-)-DIOP ((2,3-O-Isopropylidene)-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane) is used as a ligand, the addition of 4-methoxybenzenesulfonyl chloride to styrene proceeds to provide the (R) isomer in 40% ee (eq 2).8
Arenesulfonyl chlorides have also been cross-coupled in the presence of Pd0 with both vinyl- and allylstannanes to provide the corresponding sulfones.9
Kinetics on the solvolysis of various arenesulfonyl chlorides indicate an SN2 mechanism.10,11
Raj K. Raheja & Carl R. Johnson
Wayne State University, Detroit, MI, USA