Substituents, sulfonamides ortho-directing

The selective reaction of anionic 3,6-dichloro-4-sulfanilamidopy-ridazine with excess methanolic methoxide at the 3-position is another indication of the absence of major steric effects in most nucleophilic substitutions, as a result of the direction of nucleophilic attack (cf. Section II, A, 1). The selectivity at the 3-position is an example of the interaction of substituent effects. The sulfonamide anion deactivates both the 3-chloro (ortho direct deactivation) and... 

Sulfonamides as ortho-directing substituents for metalating aromatic systems opened the door to synthetic routes to cyclic sulfonic esters (sultones) and amides (sultams). The first step in this procedure for preparing sultams involved the 2-metalation of N-alkylbenzenesulfonam-ides (52) and condensation with a variety of ketones. The tertiary alco-... 

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