Compounds of general formula R1(CH2)n???X wherein R1 is ???N(H)S(O)2(C1-C4 alkyl), X is a halogen, and n is an integer ranging from 1 to 4 can be obtained by reacting an amine of formula NH2???(CH2)n???X, wherein X is a halogen, and n is an integer ranging from 1 to 4 (commercially available from Sigma-Aldrich, St. Louis, Mo. (www.sigma-aldrich.com) with a sulfonyl chloride of formula Cl???S(O)2(C