Amides sulfonate esters

Figure 38 Synthesis of PAEKs incorporating various types of functional groups. Types of X groups incorporated imide, amide, sulfone, ester, azo, quinoxaline, aliphatic, fluoroaliphatic, fluoroaromatic. (From Ref. 164.)...

Other Applications. Hydroxylamine-O-sulfonic acid [2950-43-8] h.2is many applications in the area of organic synthesis. The use of this material for organic transformations has been thoroughly reviewed (125,126). The preparation of the acid involves the reaction of hydroxjlamine [5470-11-1] with oleum in the presence of ammonium sulfate [7783-20-2] (127). The acid has found appHcation in the preparation of hydra2ines from amines, aUphatic amines from activated methylene compounds, aromatic amines from activated aromatic compounds, amides from esters, and oximes. It is also an important reagent in reductive deamination and specialty nitrile production. 

Ester eliminations are normally one of two types, base catalyzed or pyrolytic. The usual choice for base catalyzed j5-elimination is a sulfonate ester, generally the tosylate or mesylate. The traditional conditions for elimination are treatment with refluxing collidine or other pyridine base, and rearrangement may occur. Alternative conditions include treatment with variously prepared aluminas, amide-metal halide-carbonate combinations, and recently, the use of DMSO either alone or in the presence of potassium -butoxide. 

Amides Amines Esters Ethers, epxoides Halides, sulfonates... 

Feuer and co-workers also nitrated ring-substituted toluenes to the corresponding arylnitromethanes with potassium amide in liquid ammonia. Sulfonate esters and NJ -dialkylamides undergo similar nitration the latter isolated as their a-bromo derivatives. Alkaline nitration of ethyl and ferf-butyl carboxylic esters with potassium amide in liquid ammonia yields both the a-nitroester and the corresponding nitroalkane from decarboxylation. ... 

Sulfonic acids, R(Ar)S03H, form derivatives similar to those of carboxylic acids (see Table 16-3). These are sulfonyl chlorides, sulfonates (esters), and sulfonamides. The transsulfonylation reactions are similar to the transacylation reactions, except that the ester and amide cannot be made directly from the acid. See Problem 13.17 for preparation of sulfonyl chlorides and esters and Problem 13.18 for use of sulfonate esters as substrates in S l and S,42 reactions. 

Amides are very weak bases, far too weak to attack alkyl halides, so they must first be converted to their conjugate bases. By this method, unsubstituted amides can be converted to N-substituted, or N-substituted to N,N-disubstituted, amides.914 Esters of sulfuric or sulfonic acids can also be substrates. Tertiary substrates give elimination. O-Alkylation is at times a side reaction.915 Both amides and sulfonamides have been alkylated under phase transfer conditions.916... 

Various approaches have been used to prepare pyrroles on insoluble supports (Figure 15.1). These include the condensation of a-halo ketones or nitroalkenes with enamines (Hantzsch pyrrole synthesis) and the decarboxylative condensation of N-acyl a-amino acids with alkynes (Table 15.3). The enamines required for the Hanztsch pyrrole synthesis are obtained by treating support-bound acetoacetamides with primary aliphatic amines. Unfortunately, 3-keto amides other than acetoacetamides are not readily accessible this imposes some limitations on the range of substituents that may be incorporated into the products. Pyrroles have also been prepared by the treatment of polystyrene-bound vinylsulfones with isonitriles such as Tosmic [28] and by the reaction of resin-bound sulfonic esters of a-hydroxy ketones with enamines [29]. 

Peracid Precursor Systems. Compounds that can form peracids by perhydrolysis are almost exclusively amide, imides, esters, or anhydrides. Two compounds were commercially used for laundry bleaching as of 1990. Tetraacetylethylenediamine (TAED) is utilized in over 50% of Western European detergents. Nonanoyloxybenzene sulfonate (NOBS) is used in detergent products in the United States and Japan. 

Other Applications. Hydroxylainine-O-sulfonic acid has many applications in the area of organic synthesis. The acid has found application in the preparation of hydrazines from amines, aliphatic amines from activated methylene compounds, aromatic amines from activated aromatic compounds, amides from esters, and oximes. 

Procedure. A 3-ml polypropylene reaction vial was charged with a TFP-activated resin, either the carboxylate or sulfonate ester type, and 1 ml of DMF. The reaction mixture was gentle agitated for 10 min and an amine (0.065 mmol) was added. The reaction mixture was further agitated for 16 h and filtered. The resin was washed with DCM (3x2 ml) and the filtrate and washings were combined. The solvent was removed in vacuo and the amide or sulfonamide (>85% yield) so obtained was analyzed by LC/MS for purity and identity. 

Primary, secondary, and tertiary carboxylic amides, carboxylic esters, and carboxylic acids are protonated by mineral acids or sulfonic acids at the carboxyl oxygen to a small extent (Figure 6.9). This corresponds to the activation discussed in Section 6.2.3. This activation is used in acid hydrolyses of amides and esters, in esterifications of carboxylic acids and in Friedel-Crafts acylations of aromatic compounds with carboxylic acids. 

Even sulfonate esters 246 are powerful directing groups, competing well with tertiary amides. No substitution accompanies ortholithiation of ethyl or isopropyl benzenesulfonate by BuLi. Hydrolysis and chlorination of the products 247 gives functionalised sulfonyl chlorides 248.217... 

A primary or secondary amine attacks a sulfonyl chloride and displaces chloride ion to give an amide. Amides of sulfonic acids are called sulfonamides. This reaction is similar to the formation of a sulfonate ester from a sulfonyl chloride (such as tosyl chloride) and an alcohol (Section 11-5). 

An amide of a sulfonic acid. The nitrogen analogue of a sulfonate ester, (p. 903)... 

Nonaqueous solvents — Nonaqueous solvents are liquids, relevant for the preparation of solutions other than water. They can be classified in several ways protic (e.g., alcohols, acids, amines, mercaptans, i.e., having labile protons) vs. aprotic polar vs. nonpolar (e.g., paraffins, olefins, aromatic derivatives, or benzene) organic (e.g. esters, ethers, alkylcarbonates, nitriles, amides, sulfones) vs. inorganic (chalcogenides such as SOCI2, SO2CI2). Nonaqueous solvents may be superior to water in the following aspects ... 

Arylsulfonyl chlorides are pivotal precursors for the preparation of many diverse functional types including sulfonate esters,8 amides,4 sulfones,9 sulfinic acids,10 and others.11 Furthermore, sulfonyl fluorides are best prepared from sulfonyl chlorides.12 The sulfonyl fluorides have many uses, among which is their utilization as active site probes of chymotrypsin and other esterases.13 The trifluoromethyl group also plays valuable roles in medicinal chemistry.14... 

On the other hand, the substrate may undergo nucleophilic attack by base, either in the rate-determining step — with or without formation of an intermediate — or in a fast pre-equilibrium step which is followed by rate-determining breakdown of the intermediate. These three possibilities are included in the B2 mechanism according to Ingold s nomenclature [14]. Examples of one-step B2 reactions (SN2 mechanisms) are the alkaline hydrolyses of sulfonic esters [14] and 2,4,6,-tri-f-butylbenzoic esters [18]. Intermediates are formed by carbonyl addition of hydroxide ion in the alkaline hydrolyses of (unhindered) carboxylic esters and amides. Addition of OH is partially or completely rate-determining in ester hydrolysis [4, 15], but probably not in amide hydrolysis [15]. 

Sulfonyl chlorides as well as esters and amides of sulfonic acids can be hydrolyzed to the corresponding acids. Sulfonyl chlorides can by hydrolyzed with water or with an alcohol in the absence of acid or base. Basic catalysis is also used, though of course the salt is the product obtained. Esters are readily hydrolyzed, many with water or dilute alkali. This is the same reaction as 10-4, and usually involves R —O cleavage, except when R is aryl. However, in some cases retention of configuration has been shown at alkyl R, indicating S—O cleavage in these cases. Sulfonamides are generally not hydrolyzed by alkaline treatment, not even with hot concentrated alkali. Acids, however, do hydrolyze sulfonamides, but less readily than they do sulfonyl halides or sulfonic esters. Of course, ammonia or the amine appears as the salt. However, sulfonamides can be hydrolyzed with base if the solvent is HMPA. ... 

Polycondensation at room temperature between two or more fast-reacting intermediates is becoming widely used because of its convenience and speed. The interfacial polycondensation system, in particular, which employs two immiscible liquids, is applicable to a wide voriety of chemical structures amides, urethanes, esters, sulfonates, sulfonamides, and ureas. Many products can be made at low temperature which could not be formed by melt methods because of their infusibility or thermal instability. The low temperature procedures are subject to the effect of many variables, but these are readily controlled and acceptable conditions for use with new polymers or intermediates can usually be found. The processes are readily scaled up in simple batch equipment or continuous reactors. Special areas of application are the direct formation of fibers from the reactants and polycondensation on fiber substrates. 

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