Sulfonamides commercially available

Another point for structural diversification is the sulfonamide group. Imai had already shown that a wide variety of groups could be introduced at this position to optimize the reaction. Since a wide variety of sulfonyl chlorides are commercially available, a number of different types of groups could be examined (Scheme 3.34). Testing of a variety of aryl and alkyl groups on the 1,2-cyclohexanediamine backbone demonstrates that the simple methanesulfonamide 122 is clearly superior or equal to many other analogs in the cyclopropanation of cinnamyl alcohol (Table 3.11). Another concern which was directly addressed by this survey was the question of catalyst solubility. 

The initial studies of LSDAs were carried out with oleochemicals because of their structural similarity to soap. However, since the molecular structure of an efficient LSDA is characterized by a bulky hydrophilic polar head attached to a long hydrophobic tail, it is also possible to prepare LSDAs from petrochemicals. Sulfated sulfonamide derivatives of alkylbenzenes, such as commercially available detergent alkylates, were synthesized as follows [17] ... 

As occurred with the other antibiotics, commercial immunoassay formats, also available as kits for tetracyclines and penicillins such as the Parallux, the LacTek, or the Charm II, have also been placed on the market for the analysis of sulfonamides (see Table 4). Thus, the Parallux detects sulfamethazine and sulfadimethoxine in raw milk with a LOD of 10 pg L1. The Charm II detects almost all sulfonamides in honey and milk with a LOD in the range from 1 to 10 pg L, whereas LacTek is able to detect sulfamethazine. Moreover, the 5101SULlp and 5101SUDAlp tests reach LOD values for sulfamethazine and sulfadiazine of around 0.2 pg L 1 and they have been applied to the analysis of urine, milk, and plasma. These tests have proved to be efficient as a point of care for on-site applications on farms. Moreover, commercially available antibodies can be found from several sources such as Silver Lake Research, US Biological, Cortex Biochem. Inc., Accurate Chemical Scientific, Fitzgerald Industries International Inc., and Biotrend Chemikalien GmbH. 

In thin-layer chromatographic methods, sulfonamide residues were first separated on commercially available silica gel plates using various solvent mixtures as mobile phase, and subsequently detected by fluorometry after spraying... 

The Paal-Knorr method can be applied to the synthesis of a variety of 1-substituted pyrroles using commercially available 2,5-dialkoxytetrahydrofurans as a butane-1,4-dial equivalent. When an appropriate tetrahydrofuran derivative is available, the reaction can be used for more highly substituted pyrroles. Aliphatic and aromatic amines react readily and even weakly nucleophilic sulfonamides undergo cyclization (equation 66) (73SC303). 

Because many more alcohols than alkyl halides are commercially available, the Mitsu-nobu reaction enables the synthesis of larger and more diverse compound arrays than alkylation with alkyl halides. A -AcyIsuIfonamides are strongly acidic and can be alkylated with diazomethane (Entry 6, Table 8.9) or trimethylsilyldiazomethane [137]. Resin-bound sulfonamides have been N-acylated by treatment with acyl halides, and N-carbamoylated by treatment with isocyanates [138]. 

The simplest 1,3-dipolar cycloadditions of diazomethane were presented in Figure 15.36. Diazomethane is generated from sulfonamides or alkyl carbamates of A-nitrosomethylamine. The preparation shown in Figure 15.40 is based on the commercially available />ara-toluene-sulfonylmethylnitrosamide (Diazald ). In a basic medium, this amide forms a sulfonylated... 

The chiral sulfonamide 45, which can be prepared in two steps from commercially available (I R,2S)-cis-1 -amino-2-indanol (44), was introduced by Ghosh and Onishi for the synthesis of enantiomerically pure anft -aldol products via titanium enolate19a (Scheme 2.2q). 

The chloramine derivatives (ArS02NClNa) of a variety of other aryl-sulfonamides (Ar = phenyl, o-tolyl, p-chlorophenyl,/>-nitrophenyl, and o-carboalkoxyphenyl) have been used successfully in these catalytic oxy-aminations. Since only chloramine-T (Ar = p-tolyl) and chloramine-B (Ar = phenyl) are commercially available, we have developed a convenient procedure for generating the chloramines in situ for use in the modification involving phase-transfer catalysis. One simply stirs a suspension of the arylsulfonamide with an equivalent of sodium hypochlorite (Clorox) until a homogeneous solution is obtained. When this solution is used in the PTC method (see Ref. 2 for experimental details), the yields of oxyaminated product are comparable with those obtained with isolated chloramine salts. 

A one-pot procedure designed for the aziridination of a series of styrene derivatives employs commercially available iodobenzene diacetate [PhI(OAc)2] and sulfonamides (427, RSO2NH2) to generate the nitrene precursors [iV-(arene/methanesulfonyl)imino]phenyliodanes (RS02N=IPh) in situ. The reaction is carried out in the presence of the chiral catalyst CuIMeCNIaClOa-L (436 L = 2,2-bis[2-[(4A)-/-butyl-l,3-oxazolinyl]]propane) to give aziridine 437 (Scheme 113) <2004TL3965>. 

Preparative Methods The enantiopure sulfonamide la is prepared via sulfonylation of (7 ,7 )-l,2-diaminocyclohexane 2 in the presence of an excess of triethylamine (eq 1). Use of excess amine base is essential for obtaining a high yield of the bis-sulfonamide. Synthesis of related bis-sulfonamides is easily accomplished by substituting the desired sulfonyl chloride in the former procedure. Recrystallization of the bis-sulfonamide la from hexane/ethyl acetate and drying over P2O5 allows for isolation of the analytically pure reagent. Methanesulfonyl chloride and (7 ,/ )-l,2-diaminocyclohexane 2 are commercially available from a number of sources. However it should be noted that racemic 1,2-diaminocyclohexane 2 can be resolved via formation of the tartrate salt. Typically, the diamine can be obtained in >99 1 enantiomeric ratio (er) after two crystallizations from water. Determination of the enantiopurity of the diamine is accomplished via formation of the bis-3-toluyl amide and anal-... 

A number of related catenanes, including systems assembled directly from commercially available precursors and a system based on sulfonamide linkages, have also been described. 

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