Triethylbenzylammonium bromide

Methoxyimino-0 -(2-aminothiazol-4-yl)acetamido] cephalosporanic acid trifluoroacetic acid salt is dissolved in a solution of 272 mg of 1 -methyl-S-mercapto-l H-tetrazole, 555 mg of sodium bicarbonate and 68 mg of triethylbenzylammonium bromide in 10 ml of water. The solution is heated at 60°C in nitrogen atmosphere for 6 hours. After cooling, the reaction solution is passed through a column of Amberlite XAD-2 and eluted with water and then with 2.5% ethanol. The procedure yields sodium 7(3-[0 -methoxyimino-0 -(2-aminothiazol-4-yl)ace-tamido] -3-(1 -methyl-l H-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylate, MP 174°C to 175°C (decomposition). 

With triethylbenzylammonium bromide (TEBA) as the catalyst on a macro-porous styrene support cross-linked with 12% of divinylbenzene, the following kinetic rate constants k have been obtained (Table 6). It is noteworthy to observe that the apparatus FB-UM gives a rate constant very close to that of the SR-UM with the advantage of avoiding pulverization of the catalyst. Therefore, the FB-UM apparatus can be proposed for any reaction using a solid catalyst and an ultrasonic source to increase the reactivity with respect to silent conditions. ... 

Confirmation of this effect was obtained by carrying out experiments in the presence of added nucleophiles (in the form of triethylbenzylammonium chloride, or tetrabutylammonium bromide)which modified both the product ratio and the overall reaction rate. 

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