Para-nitrobenzenesulfonyl chloride

In the alternate approach, the amide formation is performed on para-nitrobenzenesulfonyl chloride (91). Reduction by either chemical or catalytic methods affords directly the desired product (90). ... 

Matsushima and Kino [544] have obtained the enantiomer of 429 applying AD-mix-)3-cat-alyzed dihydroxyiation of 427. Selective monosilylaltion with (f-Bu)Me2SiCl affords 438 (93% ee). After esterification of the allylic alcohol 438 with para-nitrobenzenesulfonyl chloride and subsequent sulfonate displacement with NaN3 (Sn2) azide 439 is isolated in... 

In l-chloro-2-nitrobenzene, sulfonation by excess chlorosulfonic acid occurred para to the chlorine atom as would be anticipated " and with l-chloro-4-nitrobenzene, the expected product, namely 2-chloro-5-nitrobenzenesulfonyl chloride, was also obtained. ... 

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