Imidazoline cationics

The reaction conditions can be selected to maximise the formation of imidazoline cationics quatemised derivatives of which have some importance as cationic fabric softeners [22c, 98, 99, 102]. Surface-active tertiary amines can be formed from alkyl chlorides, acyl chlorides or fatty esters as can be illustrated by the following reactions ... 

Amphoteric Detergents. These surfactants, also known as ampholytics, have both cationic and anionic charged groups ki thek composition. The cationic groups are usually amino or quaternary forms while the anionic sites consist of carboxylates, sulfates, or sulfonates. Amphoterics have compatibihty with anionics, nonionics, and cationics. The pH of the surfactant solution determines the charge exhibited by the amphoteric under alkaline conditions it behaves anionically while ki an acidic condition it has a cationic behavior. Most amphoterics are derivatives of imidazoline or betaine. Sodium lauroamphoacetate [68647-44-9] has been recommended for use ki non-eye stinging shampoos (12). Combkiations of amphoterics with cationics have provided the basis for conditioning shampoos (13). 

Some examples of organic anionic inhibitors are sodium phosphates, thioureas and sodium MBT phosphionates (mercaptobenzothiazole). Some examples of organic cationic inhibitors are amines, amides, quaternary ammonium salts, and imidazoline. 

Some amphoteric softeners such as amino acids (10.237) and sulphobetaines (10.238) are more effective and durable than the nonionic types but less durable than the cationics moreover, they tend to be expensive. Other amphoteric types include the zwitterionic forms of quaternised imidazolines (10.239) long-chain amine oxides (10.240) also exhibit softening properties. 

On studying electrochemical properties of l-hydroxy-3-imidazoline-3-oxides and their conversion into nitronyl nitroxyl radicals (NNR), the intermediate production of a nonaromatic radical cation (220) of AH -imidazole-1,3- dioxides (219) (Scheme 2.78) (101) was suggested. 

Unlike the 4H- imidazoles (219), (223), (224) electrochemical oxidation of the nitrone group in 4-R-3-imidazoline-3-oxides (228), (230-232), as in a-PBN and DMPO is of irreversible nature. Therefore, the formation of radical cations... 

Owing to the existence of two centers for nucleophilic attack (at C2 and C5) in radical cations (220) obtained from the oxidation of 4-H -imidazole-1,3-dioxides (219), the formation of two products of methoxy group addition was observed, namely NNR (221) and NR of 3-imidazoline-3-oxide (222). The ratio of the products depends on the electronic nature of substitutes R1 and R2. Both, the donor character of R1 and acceptor character of R2 facilitate the formation of nitroxyl radicals (222) with the yield of (221) increasing with the inverted effect of the substituents. As was mentioned in Section 2.4, the results of preparative electrochemical oxidative methoxylation of 4H -imidazole-1,3-dioxides are similar to the results of chemical oxidation. 

Oxidative Fluorination of Nitrones to a-Fluorosubstituted Nitroxyl Radicals Formation of nitroxyl radicals by the radical cation route was observed in reactions of various nitrones with xenon difluoride in dry methylene chloride (520, 523). In this reaction, more than 40 nitrones, including 4H -imidazole N,N -dioxides (219), 4H -imidazole TV-oxides (223) and (224), 2H -imidazole N -oxides (225), 2H -imidazole TV,TV-dioxides (226), 3,3,5,5-tetramethylpyrroline N -oxide (TMPO), derivatives of 3-imidazoline-3-oxides (231) and (232), have been examined. ESR spectra of nitroxyl radicals containing one or two fluorine atoms at a-C have been registered (Scheme 2.108) (523). In the case of... 

The only cationic surfactant (Fig. 23) found in any quantity in the environment is ditallow dimethylammonium chloride (DTDMAC), which is mainly the quaternary ammonium salt distearyldimethylammonium chloride (DSDMAC). The organic chemistry and characterization of cationic surfactants has been reported and reviewed [330 - 332 ]. The different types of cationic surfactants are fatty acid amides [333], amidoamine [334], imidazoline [335], petroleum feed stock derived surfactants [336], nitrile-derived surfactants [337], aromatic and cyclic surfactants [338], non-nitrogen containing compounds [339], polymeric cationic surfactants [340], and amine oxides [341]. 

Photolysis of cationic alkoxycarbene iron complexes [193] or alkoxycarbene manganese complexes [194] has been used to replace carbonyl groups by other ligands. The alkylidene ligand can also be transferred from one complex to another by photolysis [195], Transfer of alkylidene ligands occurs particularly easily from diaminocarbene complexes, and has become a powerful synthetic method for the preparation of imidazoline-2-ylidene complexes [155,196]. 

One type of cationic surfactant was the fatty acid derivatives of polyamines. The properties of the derivatives of fatty acids and ethylenediamine have been described in the literature (7-9). It appeared from these reports that the 2-alkyl-2-imidazolines would not impart sufficient hydrophobicity to soils. However, the analogous series of homologous compounds from the fatty acids and diethylene-triamine (BETA) appeared likely to do so because of their higher molecular weight. 

Chiral 2-imidazoline dianions undergo one-electron oxidation in the presence of TEMPO (2,2,6,6-tetramethyl-l-piperidinyloxy) to form a radical anion that is either trapped stereoselectively by TEMPO or undergoes dimerization. Oxidation of bis-diazene oxides leads to novel (9-stabilized 4N/3e radical cations and 4N/2e dications. These were detected by ESR spectroscopy and cyclic voltammetry. B3LYR/6-31G calculations confirmed the nature of the 4N/3e and 4N/2e systems. ... 

The simplest systems containing two conjugated ring nitrogens are 2-imidazolines [77], which are cyclic amidines and give cations [78]. 

A higher analogue of 2-imidazolines, which has recently been examined by nmr (Lloyd et al., 1973) is 2,3-dihydro-lH-l,4-diazepine [80], which protonates on the imino-nitrogen to give cation [81]. Nmr spectra show that this has a half-chair shape, which inverts rapidly at room temperature. 

The broader subject of the interaction of stable carbenes with main-group compounds has recently been reviewed. Accordingly, the following discussion focuses on metallic elements of the s and p blocks. Dimeric NHC-alkali adducts have been characterized for lithium, sodium, and potassium. For imidazolin-2-ylidenes, alkoxy-bridged lithium dimer 20 and a lithium-cyclopentadienyl derivative 21 have been reported. For tetrahydropyrimid-2-ylidenes, amido-bridged dimers 22 have been characterized for lithium, sodium, and potassium. Since one of the synthetic approaches to stable NHCs involves the deprotonation of imidazolium cations with alkali metal bases, the interactions of alkali metal cations with NHCs are considered to be important for understanding the solution behavior of NHCs. 

The fact that NHCs form stable compounds with beryllium, one of the hardest Lewis acids known and without p-electrons to back donate, shows the nu-cleophilicity of these ligands. Reaction of l,3-dimethylimidazolin-2-ylidene with polymeric BeCl2 results in the formation of the neutral 2 1 adduct 23 or the cationic 3 1 adduct 24. The first NHC-alkaline earth metal complex to be isolated was the 1 1 adduct 25 with MgEt2- Whereas l,3-dimesitylimidazolin-2-ylidene results in the formation of a dimeric compound, the application of sterically more demanding l,3-(l-adamantyl)imidazolin-2-ylidene gives a monomeric adduct. ... 

Compositions and functions of typical commercial products in the 2-alkyl-l-(2-hydroxyethyl)-2-imidazolines series are given in Table 29. 2-Alkyl-l-(2-hydroxyethyl)-2-imidazolines are used in hydrocarbon and aqueous systems as antistatic agents, corrosion inhibitors, detergents, emulsifiers, softeners, and viscosity builders. They are prepared by heating the salt of a carboxylic acid with (2-hydroxyethyl)ethylenediamine at 150—160°C to form a substituted amide 1 mol water is eliminated to form the substituted imidazoline with further heating at 180—200°C. Substituted imidazolines yield three series of cationic surfactants by ethoxylation to form more hydrophilic products quatemization with benzyl chloride, dimethyl sulfate, and other alkyl halides and oxidation with hydrogen peroxide to amine oxides. 

Commercially important surfactants based on heterocyclic structures are relatively few in number (B-80MI11510) the most important are the cationic compounds derived from imidazoline (48). Cetyl pyridinium halides (49) are used as germicides and sanitizing agents. Piperidinium (50) and morpholinium (51) compounds find application in hair conditioning formulations as antistatic agents. Substituted oxazolines (52) are a class of cationic dispersants and corrosion inhibitors. 

Imidazolin-2-ones polymers, 1, 296 synthesis, 5, 466, 491 Imidazolium cations, 2-fluoro-nucleophilic substitution, 5, 413 Imidazolium chloride, 4-amino-l-methyl-2,3-diphenyl-... 

In the absence of organic solvents, Sc(OTf)3 catalysed the cycloaddition of aziridines to nitriles to produce substituted imidazolines in good to excellent yields at room temperature and in an air atmosphere. The reaction is believed to progress through a highly reactive cationic intermediate in which the aziridine nitrogen is coordinated to Sc(OTf)3.65 The phosphine-catalysed enantioselective 3 + 2-cycloaddition of buta-2,3-dienoates with arylimines yielded 2-aryl-3-pyrrolidines with 64% ee.66... 

Nitrogen cationic surfactants can also be created by the use of difunctional small molecule amines which, after formation of an amide or ester bond, leave an amine residue which is suitable for quaternization as shown in eqs 6.1.9-6.1.11. The amine residue is then reacted with a suitable alkylating agent to form the cationic. Similarly, reaction of a triglyceride with diethylene triamine gives initially the diamide which, under appropriate conditions, can be cyclized to imidazoline [16] ... 

Imidazoline derivative. Powerful liquid cationic softener especially effective on nylon tricot knits. Excellent antistatic qualities. Is suitable for solvent applications. 

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