Two step continuous-flow synthesis of benzocaine

Benzocaine (ethylp-aminobenzoate), ethyl ester ofp-aminobenzoic acid, is an anesthetic acting as a blocker of the nerve impulses and reducing the permeability of neuronal membrane to sodium iodide, it has become widespread in the pharmaceutical industry having applications as an anesthetic prior to exams such as endoscopy or as a "retarding" agent when inserted in condom. Due to the wide insertion in the pharmaceutical market, the methodologies for obtaining this molecule have already been elucidated and published in the literature, however the application of traditional reactions in refined systems, such as continuous flow are a technological bottleneck that allow approaches aimed at the optimization of productivity. Thus, the present work aimed to apply the reduction and esterification ofp-nitrobenzoic acid in one step continuous flow systems, optimizing the reaction time and sequences, in order to add relevance and technology to the process as a whole. The model applied in a continuous flow system generated extremely positive values compared to the present literature, which include results with high conversion (> 99%) and selectivity (> 99%), in residence times that reach up to a minimum of 12 s.