Isothiocyanates have a strong electrophilic character due to the reactivity of the central carbon atom N=C=S that rapidly reacts with nucleophiles based on sulphur, nitrogen and oxygen. Isothiocyanates can be obtained from various initial materials, especially isocyanides, alkenes, aldehydes or organic halides. They are usually synthesized through the acylation process of amines with the use of thiocarbonyl reagents such as thiophosgene or through condensation of the primary amine with the surplus of carbon disulfide, in an organic solvent mixed with water and followed by the process of hydrodesulfurization using hydrogen peroxide. In this thesis the classic phenyl-isothiocyanate synthesis and the microwave phenyl- isothiocyanate synthesis at 37, 50 and 80 W are presented. The product was obtained through a reaction between aniline and carbon disulfide in an aqueous solution of potassium carbonate which produces a dithiocarbamate intermediate which was further desulfurized with cyanuric acid at 0 °C. By using the classic synthesis the smallest product mass of 4,44 g is obtained while by using the microwave phenyl- isothiocyanate synthesis at 37 W the largest mass of 6,16 g is obtained. In all synthesized products a certain amount of impurities was determined that should be removed. In addition, the amount of impurities to target product ratio is lowered in favour of the product as power of the microwave radiation increases. Identification of the synthesized compounds was conducted using spectroscopic techniques such as: Fourier-transform infrared spectroscopy (FTIR), gas chromatography with flame ionization detector (GC-FID), gas chromatography with mass spectrometer system (GC-MS) and nuclear magnetic resonance spectroscopy (NMR).