| Abstract: | Reaction of m-terphenyl with 20% oleum at 100° gives both disulfonation and double sulfonyl bridging to yield benzo1]thieno2,3-b]dibenzothiophene-3,9-disulfonic acid 5,5,7,7-tetraoxide, isolated as the disodium salt (24%) and convertible (via the disulfonyl chloride) to the bis-sulfonanilide (44%) and the bis-N-butylsulfonamide (40%). Analogously, reaction of m-terphenyl with chlorosulfonic acid at 100° gives disulfonation plus only single sulfonyl bridging to produce 2-(4-chlorosulfonyl)-7-chlorosulfonyldibenzothiophene 5,5-dioxide (80%), convertible to the corresponding bis-sulfonanilide (63%) and the bis-N-butylsulfonamide (45%). |
