Sulfonic acid chlorides hydrazides

Sulfonic acid hydrazides from sulfonic acid chlorides... 

Sulfonic acid hydrazides, RSO2NHNH2, are prepared by the reaction of hydraziae and sulfonyl haUdes, generally the chloride RSO2CI. Some of these have commercial appHcations as blowiag agents. As is typical of hydrazides generally, these compounds react with nitrous acid to form azides (26), which decompose thermally to the very reactive, electron-deficient nitrenes (27). The chemistry of sulfonic acid hydrazides and their azides has been reviewed (87). 

All the sulfonic acid hydrazides are made from hydrazine or semicarbazide and the appropriate sulfonyl chloride in the presence of an HCl acceptor such as ammonia. 

This reaction, parallel with 10-77, is the standard method for the preparation of sulfonyl halides. Also used are PCI3 and SOCI2, and sulfonic acid salts can also serve as substrates. Sulfonyl bromides and iodides have been prepared from sulfonyl hydrazides (ArS02NHNH2, themselves prepared by 10-126) by treatment with bromine or iodine.Sulfonyl fluorides are generally prepared from the chlorides, by halogen exchange. 

The two isomeric sulfonyl chlorides 134 and 135 were obtained in approximately equal amounts and the additional o-sulfonation may occur by an intramolecular mechanism. The chlorosulfonation of 2,6-dihalophenols by chlorosulfonic acid and the subsequent condensation of the 4-sulfonyl chloride with secondary amines, e.g. A/-methylaniline, yields sulfonjunides, like 3,5-dibromo-4-hydroxy-iV-methylphenylsulfonamide, which is an effective herbicide against wild oats. The various dichlorohydroxybenzenesulfonyl chlorides were converted into sulfonamides, hydrazides and azides for screening as novel biocides. o-Chlorophenol 136, by heating with chlorosulfonic acid (eight equivalents) at 100°C (1 hour), gave the 1,3-disulfonyl chloride 137 (59%) (Equation 44). 

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