The synthesis of thiazolyl-7-aminocephalosporanic acid, a pharmaceutical precursor of the beta-lactam antibiotic drug cefodizime, could be successfully realized in a continuous microstructured flow system. This was accomplished by changing the process window from batch, having a reaction temperature of 60 degrees C with a reaction time of 1 h, to a flow system at temperatures > 100 degrees C and reaction times of several minutes. The space-time yield could be increased by a factor of 130.