Thiophene-2-carboxanilide, the £-chloro,bromo, nitro derivatives and N-(2'-pyridyl) thiophene-2-carboxamide reacted with chlorosulphonic acid to give the sulphonyl chlorides (I, VIII, XIV, XVI, XVIII). The yields were comparatively low when electron-withdrawing groups were present, e.g. nitro and 2-pyridyl. With the £-carboxy derivative only thiophene-2-carboxylic acid was isolated and the £-methyl derivative gave an unidentified product. Furan-2-carboxanilide with chlorosulphonic acid afforded the sulphonyl chloride (XXII). With the unsubstituted heterocyclic carboxanilides, sulphonat i on occurred in the phenyl ri ng to gi ve (I, XX I I) but with subst ituted anilides reaction occurred preferentially in the 4-position of the heterocyclic nucleus. The spectral data of the compounds are briefly discussed.
O O SHODE ,F J SWINBOURNE ,R J CREMLYN ,
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