Sulfonamido derivatives

Relatively little data are available on sulfonamido derivatives of heterocyclic systems with five-membered rings. The tautomeric equilibrium between structures 222 and 223 has been shown to favor the imine form by about 10 1 by comparison of the ultraviolet spectrum of the parent compound with those of both methylated forms." ... 

The large importance of the sulfonamides for chemotherapeutics, and specially the high activity of sulfathiazole toward bacterial infections, indicated that sulfonamido derivatives of selenazole should also be investigated. Backer and de Jonge used for this purpose 2-amino-... 

IV-Sulfonylation. The /V-sulfonylation reaction (Scheme 42) was performed using different sulfonyl chlorides and some enantiopure sulfonamido derivatives were synthesized.54 The TV-selectivity of sulfonylation was ascertained by 13C NMR.62... 

The replacement of the reactive 5-chloro by a sulfonamido group in 1,2,4-thiadiazoles affords a convenient synthesis of the 5-sulfonamido heterocycles.92- 3,168-172 173 Thus, 5-halogeno compounds (171), on treatment with p-acetamidobenzenesulfonamide and potassium carbonate in diphenyl ether at 200°, afford the sulfonamido derivatives (170) in 70 % yields. Nitrobenzenesulfonamides do not react. This route is valuable, because the products are obtainable with difficulty by sulfonylation of the parent amine (see Section III,D, 1,A).8-8S-86-87 The superiority of route 171 -> 170 over route 169-y 170, though unusual in the heterocyclic field, recalls similar observations made in the synthesis of sulfonamidotriazines.174... 

Special mention obviously must be given to sulfonamido derivatives of the thiazole ring. A complete coverage of the field is beyond the scope of this review however, some examples of their activity may be given here ... 

MO calculations on the sulfonamido derivatives of 2-amino- and 2-amino-5-methyl-l,3,4-thiadiazole are also available. Using the LCAO-MO method, a correlation between pKa and the electronic charge at the nitrogen atom adjacent to the S02 group can be obtained (67JPS608). 

O Neal, J.S. Schulman, S.G. Fluorescence polarization immunoassay of phenytoin employing a sulfonamido derivative of 2-napththol-8-sulfonic acid as a lablel. Anal. Chem. 1984, 56, 2888-2891. 

Substitution. Secondary benzylic and allylic alcohols are converted to carboxamido and sulfonamido derivatives by amides and sulfonamides, respectively, in the presence ofFeClj/ ... 

A-Alkylated amino acids can be obtained analogously from halo aliphatic acids and alkylamines. For instance, keeping 5 g of L-2-bromopropionic acid in 15 ml of 33% aqueous methylamine solution for 2 days afforded 71% of L-iV-methylalanine.518 Alkylation of sulfonamido derivatives, mentioned above, can also be applied to the synthesis of alkylamino acids 518,519 Fischer and Lipschitz519 synthesized TV-methylleucine from leucine by preparing and methylating the iV-tosyl derivative. 

A rather new technique is APPI, which has only been applied in two studies to determine PFOS [57] in river waters and FTOH and sulfonamido derivatives in biotic samples [58]. APPI is a very selective tool and, in stark contrast to ESI, is considered to be virtually imperceptible to matrix effects, which was confirmed in both studies. APCI and especially APPI are not recommended for metabolism studies of unknown compounds, since ionization is very delicate with these methods. Therefore, unknown compounds may not be discovered due to a lack of ionizability. ESI is the method of choice due to the wide range of ionizable compounds after LC separations. 

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