Continuous system with microwave irradiation to obtain alkyl benzoates

In this study, a continuous linear alcohol derivatization is developed. Reaction of alcohol group (ROH) with benzoyl chloride (BC) is carried out in an on-line system with UV detection. All reaction conditions, as flow rate (FR), ROH/BC molar ratio, wavelength, temperature, microwave (MW) irradiation and reaction coil size (internal diameter and length) were optimized. 0.5 mL min−1, 2.49 [BC]/[ROH], 230 nm, 60 °C or medium power (225 W) when MW irradiation was used and a reactor coil of 159 μL (0.5 mm × 810 mm) were the optimum conditions. The on-line system with microwave irradiation was more efficient than the one with a water bath heating. The developed system reduces analysis time consumption, reagent amounts and this system was used to evaluate the composition of commercial samples of alcohols polyethoxylated (surfactants).