Alkyl chlorides, preparation VOLUME

OleFns and Fatty Alcohols. Alkylbenzyldimethylammonium (ABDM) quatematies are usually prepared from a-olefin or fatty alcohol precursors. Manufacturers that start from the fatty alcohol usually prefer to prepare the intermediate alkyldimethylamine direcdy by using dimethylamine and a catalyst rather than from fatty alkyl chloride. Small volumes of dialkyldimethyl and alkyltrimethyl quatematies in the Cg—range are also manufactured from these precursors (Fig. 4). 

Diphenyl Tellurium Bis[0-alkyl dithiocarbonates]1 A solution of 7.7 g (21.75 mmol) of phenyl tellurium dichloride in 20 ml absolute tetrahydrofuran is cooled to — 40°. A freshly prepared solution containing the stoichiometrically required amount of sodium O-alkyl dithiocarbonate is slowly dropped to the tellurium compound. The mixture is stirred for 1 h and allowed to warm to 0". The sodium chloride is removed by filtration. The filtrate is concentrated at 0° under reduced pressure to one third of its volume. The solid is collected by filtration and recrystallized from cold petroleum ether or chloroform/pentane mixtures. These operations should be carried out quickly to avoid the decomposition of the products in the dissolved state. Prepared in this or similar manner were ... 

Fu and Mak [238,239] dealt with acyl alkyl esters of amino acids with various combinations of acyl and alkyl moieties in comprehensive studies. They evaluated and determined optimal conditions for their preparation they selected acylation with the aid of the anhydride or chloride of the appropriate acid as the first step. They performed the reaction at 20-30°C with vigorous stirring for 10 min, with subsequent esterification with the appropriate alcohol in dry benzene in the presence of Amberlite IR-120 (H+). They further evaluated their retention properties on both Carbowax 20M and GE-XE-60, and the relationships between these properties and their structure. Kolb and Hoser [240] described a microdevice in which the derivatives were prepared with the aid of opened aluminium or gold capsules (20-/J volume) which acted as a microreactor in an automatic capsule—dosage system (MS 41). As an example they demonstrated the application of their device to the preparation of HFB-methyl esters. 

Previously, the most widely used method for preparation of 4-alkyl-benzoyl chlorides on a laboratory scale has been from the benzoic acids obtained by oxidation of aromatic ketones, usually 4-alkylacetophe-nones. 14 The latter are usually prepared by acylating alkylbenzenes. Although this sequence gives high yields, it is lengthy (three completely separate steps) and the scale is restricted in the second step because of the large volumes required. The submitters state that they were unable to repeat the reported alkylation of toluic acid.15 Methods that lead to formation of ortho and para isomeric intermediates are inconvenient since they require that the isomers be separated.16"19... 

To prepare the [m-(acetylpyridinio)-n-alkyl]adenosine pyrophosphates, 10 mmoles of acetylpyridinio-n-alkylphosphoric acid and 10 mmoles of adenosine 5 -phosphoromorpholidate (as salt of 4-morpholine iV,iV -dicyclohexylcarboxamidine) are dissolved in 20 ml of freshly distilled o-chlorophenol. The mixture is stored at room temperature for 7 days. Progress of the condensation reaction is checked daily by paper electrophoresis (0.1 M Tris chloride at pH 8.1, 30 V/cm). After the reaction is completed, 60 ml of water are added to the mixture and the suspension is extracted 3 times, each with 200 ml of ethyl ether. The first ether extract obtained is reextracted with 30 ml of water. The combined aqueous phases are reduced to a volume of 5 ml under reduced pressure and are charged on to a Dowex 1X8 column (formate form, 2 X 50 cm, 100-200 mesh). The column is washed with 6.5 liters of water, and the coenzyme analogs are eluted from the resin with a convex gradient of formic acid ... 

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