Dimethyl dialkyl quaternary

Nanomer I.44PA dimethyl, dialkyl quaternary ammonium... 

QuaterniZation. Quaternary ammonium compounds are formed by alkylation of alkyl, alkyl dimethyl, dialkyl, and dialkylmethyl fatty amines with methyl chloride, dimethyl sulfate, or benzyl chloride (1,3,7,12,29). 

Alkylation can lead to several products. When heated in a variety of solvents with alkyl halides, 2-imidazolines give low yields (30-40%) of l-alkyl-2-imidazolines, accompanied by some 1,3-dialkyl quaternary salts. If water is present these salts are readily hydrolyzed to aliphatic secondary diamines. In the presence of reducing agent, e.g. Ha/Ni, l-benzyl-2-imidazoline is methylated at N-1 by formaldehyde. When 2,2,4-triethyl-5-methyl-3-imidazoline (174) is treated with dimethyl sulfate in aqueous alkali the 1-methyl product is formed (Scheme 84). 

Adducts from various quaternary salts have been isolated, in reactions with aldehydes, a-ketoaldehydes, dialkylacylphosphonates and dialkyl-phosphonates, isocyanates, isothiocyanates, and so forth (Scheme 15) (36). The ylid (11) resulting from removal of a Cj proton from 3.4-dimethyl-S-p-hydroxyethylthiazolium iodide by NEtj in DMF gives with phenylisothiocyanate the stable dipolar adduct (12) that has been identified by its NMR spectrum and reactional product, such as acid addition and thiazolidine obtention via NaBH4 reduction (Scheme 16) (35). It must be mentioned that the adduct issued from di-p-tolylcarbodiimide is separated in its halohydrogenated form. An alkaline treatment occasions an easy ring expansion into a 1,4-thiazine derivative (Scheme 17) (35). 

The single largest market use for quaternary fatty amines is in fabric softeners. Monoalkyl quaternaries (chloride) have been used in Hquid detergent softener antistat formulations (LDSA), dialkyl dimethyl quaternaries (chloride) in the rinse cycle, and dialkyl dimethyl quaternaries (sulfate) as dryer softeners. 

Another significant use for dialkyl dimethyl quaternary ammonium salts and alkylhenzyl dimethyl ammonium salts is in preparing organoclays for use as drilling muds, paint thickeners, and lubricants. 

IV-Methylated pyridazinones can be obtained from 3,6-dialkoxypyridazines by treatment with alkyl halides or dialkyl sulfates. Methyl iodide and dimethyl sulfate are most frequently used. According to the proposed mechanism, an intermediate quaternary pyridazinium salt is formed, followed by elimination of a group R from the alkoxy group. At higher temperature, l,2-dimethylpyridazine-3,6(l//,2//)-dione is formed with dimethyl sulfate. 

In contrast with the reactions involving sulphide or hydrogen sulphide anions, aryl alkyl thioethers and unsymmetrical dialkyl thioethers (Table 4.3) are obtained conveniently by the analogous nucleophilic substitution reactions between haloalkanes and aryl or alkylthiols under mildly basic conditions in the presence of a quaternary ammonium salt [9-15] or polymer-supported quaternary ammonium salt [16]. Dimethyl carbonate is a very effective agent in the formation of methyl thioethers (4.1.4.B) [17]. 

Table 2. Yield, 001 spacings, layer charge and dialkyl dimethyl quaternary ammonium (AMQA) cation content for the organophilic hectorites...

Typical synthetic procedures include the reaction of alkyl halides with the silver salts of carboxylic acids, the reaction of carboxylate anions in alkali with an excess of a dialkyl sulphate, (especially dimethyl sulphate), and heating tertiary184 or quaternary ammonium salts of carboxylic acids. These routes are particularly valuable for the preparation of esters of seriously sterically hindered acids. For example, Fuson et al.iK made the methyl ester of 2,4,6-triethylbenzoic acid by heating the tetramethyl ammonium salt to 200-250°C, viz. 

Although phenols, chlorophenols, alcohols, hypochlorites, and iodophors are used as active biocide agents against certain strains of bacteria in some applications, formulations with quaternary ammonium compounds as the active biocide ingredients account for the majority of all l I sanitizers and disinfectant products. A variety of known quaternary ammonium compounds are effective, but the quaternary compound of choice is dialkyl dimethyl ammonium chloride. 

Patton, C. C., 1991. Applied Water Technology, Campbell Petroleum Series, Second Printing, Norman, OK, and references therein. Petrocci, A. N., Green, H. A., Merianos, J. J. and Like, B., 1974. The properties of dialkyl dimethyl quaternary ammonium compounds. 

The water solubility of quaternaries primarily depends on the nature of R substituents (hydrophobic chain lengths, polarity, etc.). Quaternaries carrying two or more long hydro-phobic chains have very poor water solubility. On the other hand, iST-alkyltrimethyl ammonium salts and short-chain dialkyl or alkyl/aryl (e.g., benzylalkyl) dimethyl ammonium salts often show much better solubility. 

Quaternary ammonium compounds having one and/or two hydroxyethyl groups Sodium dialkyl sulfosuccinate Dicoco dimethyl ammonium chloride Soaps... 

Elution of compounds in a normal phase system is in reverse order of alkyl character (Fig. 8). Thus, trialkylmethylammonium compounds elute first, followed by dialkyldimethylammonium compounds, quaternary imidazoline derivatives, alkyldimethylbenzylammo-nium compounds, and finally monoalkyltrimethylammonium compounds (185,186). Under the proper conditions, partial resolution by chain length can be obtained of the dialkyl dimethyl quaternaries (187) or of the monoalkyltrimethyl compounds (186,188), with the higher carbon number compounds eluting first. 

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