Synthesis of sulfanilyl fluorides

Baker and his colleagues have prepared a series of sulfonyl fluorides as 

One group of compounds prepared had the general structure of XIV which could be synthesized by the indicated route. As presented in the synthetic scheme, the sulfonyl fluoride moiety was introduced as 

The synthesis of N-(m-nitrobenzoyl)sulfanilyl fluoride (XII, n = 0) by Baker and Lourens (1967) was performed as follows. A mixture of 1.75 g (10 mmoles) of sulfanilyl fluoride (XI), 1.86 g (10 mmoles) of ffj-nitrobenzoyl chloride, and 50 ml of xylene was refluxed for 2 hr during which time about 15 ml of the xylene was allowed to distill and HCl was evolved. The mixture was cooled, the product was collected 

The same authors synthesized N-(m-aminobenzoyl)sulfanilyl fluoride (XIII, n=0) in the following manner. A suspension of 1.95 g (6 mmoles) of (XII, n=0) and 1 g of Raney nickel (Grace Co.) in 100 ml of EtOH was shaken with at 2-3 atm until 18 mmoles of H2 was absorbed (20 min). The solution was filtered through a celite pad and the filter cake was washed (EtOH). The combined filtrate and washings were concentrated to about 10 ml on the rotary evaporator and then diluted (H2O) and cooled. The solid product was collected and recrystallized from aqueous EtOH yield, 1.00 g (57 %) of buff crystals, m.p. 200-204°C dec. 

The last step in the synthesis of the affinity label XIV involved the following steps. A mixture of 589 mg (2 mmoles) of XIII, 185 mg (2,2 mmoles) of cyanoguanidine, 15 ml of reagent acetone, and 0.18 ml of 12 N HCl was refluxed with stirring for 24 hr, during which time the product crystallized from the solution. The cooled mixture was filtered and the product was washed with acetone. Recrystallization from ethanol gave 380 mg (42 %) of white crystals, m.p. 231-233°C dec. 

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