Versatile reagent in synthetic chemistry, often utilized to introduce nitrogen into a more complex organic compnd. Prepn from 4-nitrobenzenesulfonyl chloride: J. J. Blanksma, Recl. Trav. Chim. Pays-Bas 20, 121 (1901); from 4-nitrobenzenesulfinic acid: P. R. Carter, D. H. Hey, J. Chem. Soc. 1948, 147 DOI. 13C, 15N, and 17O NMR studies: P. Ruostesuo et al., Magn. Reson. Chem. 25, 189 (1987) DOI. Crystal structure: M. Tremayne et al., Acta Crystallogr. B58, 823 (2002) DOI. Dissociation constant determn studies: A. V. Willi, Helv. Chim. Acta 39, 46 (1956) DOI; M. Ludwig et al., Collect. Czech. Chem. Commun. 49, 1182 (1984). Carbonic anhydrase inhibition studies: A. Innocenti et al., Bioorg. Med. Chem. Lett. 14, 5703 (2004) DOI PubMed. Synthetic applications: H.-L. Kwong et al., Tetrahedron Lett. 45, 3965 (2004) DOI; G. Y. Cho, C. Bolm, ibid. 46, 8007 (2005) DOI; J. G. Taylor et al., Org. Lett. 8, 3561 (2006) DOI PubMed; M. Abid et al., Tetrahedron Lett. 48, 4047 (2007) DOI. Review: A. C. Mayer, Synlett 2008, 945-946 DOI.