Biphenyl-4,4 -disulfonyl chloride

In 1967 3M introduced polybiphenyldisulfones under the Astrel 360 trade name. This polymer was made by the Friedel-Crafts reaction of biphenyl-4,4 -disulfonyl chloride with diphenyl ether and exhibited a very high Eg of 277°C [26]. The structure is shown in Fig. 1.12. The price was very high, it was difficult to melt process, and had limited availability. This resin is no longer commercially available. 

The 3,7-disulfonyl chloride of dibenzothiophene 5,5-dioxide has been isolated from the reaction of biphenyl with chlorosulfonic acid. The reaction proceeds via the 2,4,4 -trisulfonyl chloride of biphenyl. This reaction has now been extended to give sulfonic acid derivatives of 3-phenyl- and 3-biphenylyldibenzothiophene 5,5-dioxide. Treatment of p-terphenyl with oleum or chlorosulfonic acid at 100° yields (141a) (46%), and similarly p-quaterphenyl yields 141b (47%). A later... 

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). 

Biphenyl. Biphenyl 32 gives the 4-sulfonic acid by warming with chlorosulfonic acid (one equivalent) in tetrachloroethane and by treatment with an excess of the reagent at 0 °C, the 4,4 -disulfonyl chloride 33 is formed in 80% yield (Equation 11). ... 

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... 

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