Imidazoline derivatives

RD Dghaym, R Dhawan, BA Arndtsen. The use of carbon monoxide and imines as peptide derivative synthons a facile palladium-catalyzed synthesis of a-amino acid derived imidazolines. Angew Chem Int Ed 40 3228-3230, 2001. 

Dghaym et al. reported that a-amino acid derived imidazoline 7 can be synthesized by Pd-catalyzed reaction of the imine 6, CO, and benzoyl chloride using... 

In 2004, j0rgensen and co-workers showed that 10mol% of phenylalanine-derived imidazoline 60 catalyzes the enantioselective domino Michael/aldol reaction of p-keto-sulfones 58 and p-aryl-a,p-unsaturated ketone 59 to give 61 with 86-99% ee (Scheme 22.15). ... 

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). 

Fats, Oils, or Fatty Acids. The primary products produced direcdy from fats, oils, or fatty acids without a nitrile iatermediate are the quatemized amidoamines, imidazolines, and ethoxylated derivatives (Fig. 3). Reaction of fatty acids or tallow with various polyamines produces the iatermediate dialkylarnidoarnine. By controlling reaction conditions, dehydration can be continued until the imidazoline is produced. Quaternaries are produced from both amidoamines and imidazolines by reaction with methyl chloride or dimethyl sulfate. The amidoamines can also react with ethylene oxide (qv) to produce ethoxylated amidoamines which are then quaternized. 

These compounds and their derivatives can be manufactured using relatively simple equipment compared to that required for the fatty nitrile derivatives. Cyclization of amidoamines to imidazolines requires higher reaction temperatures and reduced pressures. Prices of imidazolines are therefore high. 

In addition to the mono- and dialkylamines, representative stmctures of this class of surfactants include /V-alkyltrimethylene diamine, RNH(CH2)3NH2, where the alkyl group is derived from coconut, tallow, and soybean oils or is 9-octadecenyl, 2-aLkyl-2-imidazoline (3), where R is heptadecyl, heptadecenyl, or mixed alkyl, and l-(2-aniinoethyl)-2-aLk5l-2-imidazoline (4), where R is heptadecyl, 8-heptadecenyl, or mixed alkyl. 

Many of the surfactants made from ethyleneamines contain the imidazoline stmcture or are prepared through an imidazoline intermediate. Various 2-alkyl-imidazolines and their salts prepared mainly from EDA or monoethoxylated EDA are reported to have good foaming properties (292—295). Ethyleneamine-based imida zolines are also important intermediates for surfactants used in shampoos by virtue of their mildness and good foaming characteristics. 2- Alkyl imidazolines made from DETA or monoethoxylated EDA and fatty acids or their methyl esters are the principal commercial intermediates (296—298). They are converted into shampoo surfactants commonly by reaction with one or two moles of sodium chloroacetate to yield amphoteric surfactants (299—301). The ease with which the imidazoline intermediates are hydrolyzed leads to arnidoamine-type stmctures when these derivatives are prepared under aqueous alkaline conditions. However, reaction of the imidazoline under anhydrous conditions with acryflc acid [79-10-7] to make salt-free, amphoteric products, leaves the imidazoline stmcture essentially intact. Certain polyamine derivatives also function as water-in-oil or od-in-water emulsifiers. These include the products of a reaction between DETA, TETA, or TEPA and fatty acids (302) or oxidized hydrocarbon wax (303). The amidoamine made from lauric acid [143-07-7] and DETA mono- and bis(2-ethylhexyl) phosphate is a very effective water-in-od emulsifier (304). 

The derivatives used in corrosion inhibitor formulations for down-hole use constitute a significant industrial appHcation for polyamines. Again, mono- and bisarnidoamines, imidazolines, and polyamides made from the higher polyamines are the popular choices. The products made from DETA and fatty acids have been widely used (308). A wide variety of other polyamine-based, corrosion inhibiting derivatives have been developed, generally incorporating some form of oil-soluble or od-dispersible residue. Sulfur and its derivatives are also used in these polyamine-based corrosion inhibitors on... 

Imidazole and imidazoline derivatives have provided some useful antimicrobial compounds (Fig. 7). Metronidazole [433-48-1]... 

A -Imidazolines, -oxazolines and -thiazolines (291), and their benzo derivatives (292), are very easily aromatized (292 293), and syntheses which might be expected to yield... 

Many mercaptoazoles exist predominantly as thiones. This behavior is analogous to that of the corresponding hydroxyazoles (c/. Section 4.02.3.7). Thus oxazoline-, thiazoline- and imidazoline-2-thiones (521) all exist as such, as do compounds of type (522). However, again analogously to the corresponding hydroxyl derivatives, other mercaptoazoles exist as such. 5-Mercaptothiazoles and 5-mercapto-l,2,3-triazoles (523), for example, are true SH compounds. 

The ynaminoketones (X = Me) obtained from diacetylene react with 1,2-diaminoethane as simple ynamines by double attack at the triple bond to form imidazoline derivatives 348. 

A rather simple derivative of imidazoimidazoline has been described as an antidepressant agent. Preparation of this compound starts with the displacement of the nitramine grouping in imidazoline derivative by phenyl ethanol amine The product of this reaction is then treated with thio-nyl chloride. The probable chloro intermediate ( ) cyclizes under the reaction conditions to afford imafen (5. ... 

Napamezole (68) is a dihydroimidazole derivative with antidepressant activity probably as a result of its combined a 2 adrenergic receptor blockuig and serotonin uptake blocking proper ties It can be synthesized by Wittig olefination of p-tetralone (65) with diethyl (cyanomethyl) phosphonate (66) and base to give nitnle 67 Imidazoline construction on the latter was smoothly... 

Another imidazoline derivative, lofexidine (71), has different pharmacological properties. 

Most of the inhibitors in use are organic nitrogen compounds and these have been classified by Bregman as (a) aliphatic fatty acid derivatives, b) imidazolines, (c) quaternaries, (d) rosin derivatives (complex amine mixtures based on abietic acid) all of these will tend to have long-chain hydrocarbons, e.g. CigH, as part of the structure, (e) petroleum sulphonic acid salts of long-chain diamines (preferred to the diamines), (/) other salts of diamines and (g) fatty amides of aliphatic diamines. Actual compounds in use in classes (a) to d) include oleic and naphthenic acid salts of n-tallowpropylenediamine diamines RNH(CH2) NH2 in which R is a carbon chain of 8-22 atoms and x = 2-10 and reaction products of diamines with acids from the partial oxidation of liquid hydrocarbons. Attention has also been drawn to polyethoxylated compounds in which the water solubility can be controlled by the amount of ethylene oxide added to the molecule. 

Figure 8.9 The chemical structure of imidazole and imidazoline, together with some well-known derivatives...

A Au mdssbauer study of reaction products of trimeric l-benzyl-2-gold(I)-imidazole leading to Au carbene or Au imidazoline complexes and trinuclear Au " imidazolyl derivatives. X-Ray crystal structure of [ (p-l-benzylimidazolato-N, C )Au 3l2j. Journal of Organometallic Chemistry, 470, 275-283. 

Ligand abbreviations bi = 2,2 -bi-2-imidazoline bt = 2,2 -bi-2-thiazoline bpy = 2,2 -bipyridine phen = 1,10-phenanthroline phy = l,10-phenanthroline-2-carbaldehyde phenylhydrazone bpp = 2,6-bis(pyrazol-3-yl)pyridine paptH = 2-(2-pyridylamino)-4-(2-pyridyl)thiazole 2-pic = 2-picolylamine L = macrocyclic ligand derived from condensation of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine Hjthpu = pyruvic acid thiosemicarbazone Hjthpx = pyridoxal thiosemicarbazone salen = dianion of W,iV -ethylenebis(salicylideneimine) H2fsa2en = dianion of fV,JV -ethylenebis(3-carboxysalicylaldimine). 

Polyamides containing a-aminoacid units are readily obtained by reaction of bisazlactones (2-oxazolin-5-ones) with diamines. When polyamines such as diethylenetriamine (DETA) or triethylenetetramine (TETA) are used as the diamine component, the resultant polyamides readily cyclodehydrate above 200°C to produce polymers containing 2-imidazolin-5-one units in the backbone. Polyamides derived from simple diamines (e.g. 1,6-hexanedi amine) cyclodehydrate only in the presence of a suitable catalyst. Carboxylate salts and certain Lewis acids have been found to be efficient catalysts for this transformation. 

Chemical stabilizers have been used to reduce the rate of oxygen-promoted degradation of polysaccharides at T>225°F. Methanol and sodium thiosulfate are the most commonly used (86). Sodium dithio-carbamate, alkanolamines, and thiol derivatives of imidazolines, thiazolines, and other heterocyclic compounds have also been tested for this application. Calcined dolomite (B7) and Cu(l) and Cu(ll) salts (88) have been reported to increase the thermal stability of HEC. 

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