Biphenyl-4-sulfonyl chloride

The Friedel-Crafts cyclization of biphenyl-2-sulfonyl chloride to give dibenzothiophene sulfone has been described (55%) ° however, thermal cyclization in octachloronaphthalene at 250°, under nitrogen, is reported to yield dibenzothiophene itself rather than the sulfone (47%). Reaction of biphenyl compounds with oleum (H2SO4 + SO3) to yield derivatives of dibenzothiophene 5,5-dioxide is widely used for the preparation of dyestuff intermediates (Section VI, E, 2). A typical example is shown in Eq. (3), starting from o-tolidine. ... 

Lanthanide(III) triflates catalyze the nitration of a range of simple aromatic compounds (benzene, toluene, biphenyl, m- and p-xylene, naphthalene) in good to excellent yield using stoichiometric quantities of 69% nitric acid.276 Bismuth(III) triflate was found to catalyze sulfonylation of aromatics with aromatic sulfonyl chlorides with similar high efficiency.277... 

Benzo[6]thiophene 1,1-dioxides have been made by cyclization procedures (Section 3.15.3.1.7). Homologs of acetophenone cyclize on treatment with chlorosulfonic acid to give 2-substituted 3-chlorobenzo[6]thiophene 1,1-dioxides (equation 86). Similarly 1,1-diaryl-1-propenes in concentrated sulfuric acid gave 2-methyl-3-arylbenzo[6]thiophene 1,1-dioxides (65JOC2840). Friedel-Crafts cyclization of l,l-diphenylethylene-2-sulfonyl chloride gave 3-phenylbenzo[6]thiophene 1,1-dioxide (equation 87) (59JA2000). Treatment of various biphenyl derivatives with fuming sulfuric acid forms the dibenzothiophene 5,5-dioxides (Section 3.15.3.1.7). 

Synthetically useful routes to dibenzo[c,e J[l,2]dithiins are normally based on cyclizations of biphenyI-2,2 -disulfonyl chlorides. A method applied successfully to the parent compound reduces the precursor with zinc in acetic acid to generate the bis thiol, which is then gently oxidized to the dithiin using iron(II) chloride (66HC(21-2)952). An alternative one-step reductive cyclization, which has been applied to the preparation of the 2,9- and 3,8-dinitro derivatives, involves reduction of the appropriate bis sulfonyl chlorides with hydriodic acid in acetic acid (68MI22600). Yet another reductive cyclization uses sodium sulfite followed by acidification, and these conditions lead to dibenzo[c,e][1,2]dithiin 5,5-dioxide. The first step of the reaction is reduction to the disodium salt of biphenyl-2,2 -disulfinic acid which, on acidification, forms the anhydride, i.e. dibenzo[c,e][l,2]dithiin 5,5,6-trioxide. This is not isolated, but is reduced by the medium to the 5,5-dioxide (77JOC3265). Derivatives of dibenzo[c,e] [1,2]dithiin in oxidation states other than those mentioned here are obtainable by appropriate oxidation or reduction reactions (see Section 2.26.3.1.4). 

This synthetic strategy can be altered for the preparation of branched oligo-knotanes, which necessitate a multifunctional core and monofunctional branching units. Reaction of the monohydroxy-knotane 28 with an excess of biphenyl-4,4 -disulfony 1 chloride 42 readily gives a sulfonylated knotane 49 containing one reactive sulfonyl chloride unit. 

There are several types of polyaryl sulfones available commercially. The classic polysulfone (Udal) was produced by the nucleophilic displacement of the chlorine substituents on bis(p-chlorophenyl) sulfone by the sodium salt of blsphenol A.Another polysulfone (Astrel) is produced by the Friedel-Crafts condensation of biphenyl with oxy-bis(benzene sulfonyl chloride). Another polysulfone (Vitrex), is produced by the alkaline condensation of bis(chlorophenyl) sulfone. (28.)Blends of polysulfones with ABS (Arylon, Mlndel) and SAN (Ucardel) are available. 

Poliak et al. claimed that the reaction of biphenyl 32 with excess chlorosulfonic acid (six equivalents) at 18 °C affords dibenzothiophene-5,5-dioxide-3,7-disulfonyl chloride 34, but more recent attempts to reproduce this result were unsuccessful and only the 4,4 -disulfonyl chloride 33 (80%) was isolated. However, the cyclized product 34 was obtained in good yield (72%) when biphenyl 32 was heated with a large excess of chlorosulfonic acid (20 equivalents) at 150 °C (4 hours) (Equation 11). The reaction presumably involves the formation of the intermediate biphenyl-2,4,4 -trisulfonyl chloride, 35 which subsequently cyclizes with loss of hydrogen chloride to give the dibenzothiophene dioxide 34. Further study of the action of chlorosulfonic acid on biphenyl 32 showed that the optimum yield of the 4-sulfonyl chloride (43%) was derived from treatment of 32 with the reagent (1.5 equivalents) in thionyl chloride as solvent at 0 °C (1 week). The best yield (89%) of the 4,4 -disulfonyl chloride 33 was also achieved by treatment of the hydrocarbon 32 with chlorosulfonic acid (three equivalents) in thionyl chloride at room temperature (1 week). 

The cyclization of diphenyl ether 206 to the cyclic sulfone derivatives 208 and 209 achieved by prolonged heating with a large excess of the reagent is analogous to similar reactions observed with biphenyl and the diphenyl alkanes (see Section 2, pp 42 and 40). 4-Bromodiphenyl ether by treatment with excess chlorosulfonic acid (two equivalents) at 25-30 °C afforded the 4-sulfonyl chloride (45%). In this molecule, the other reactive 4-position is blocked by the bromine atom. In contrast, with diphenyl ether 206 all attempts to obtain the monosulfonyl chloride by reaction with chlorosulfonic acid failed, and the only isolated product was the 4,4 -disulfonyl chloride. In the case of 4,4 -dibromodiphenyl ether, in which... 

Solvents are employed to moderate the sulfonation reaction as in the case of biphenyl, where chlorosulfonic acid in chloroform or tetrachloroethane is employed to give monosulfonation. A solvent also minimizes the formation of sulfonyl chlorides. 

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