SYNTHESIS OPTIMIZATION OF 6-NITRO-3,4-DIHYDROQUINAZOLINE-4-ONE

Abstract

A method for the synthesis of the substance 6-nitro-3,4-dihydroquinazolin-4-one has been developed. Quantitative determination of the target product was carried out spectrophotometrically using an SF-46 instrument. As a solvent, 0.1 mol/l HCl was used. A 0.1 mol/l hydrochloric acid solution was used as a comparison solution. The optical density of the standard and test samples was measured at a wavelength of 254 nm. The synthesis conditions of 6-nitro-3,4-dihydro-quinazolin-4-one were studied. The structure of the obtained product was studied by IR, Mass, 1H, 13C NMR spectroscopy, and the structure of the synthesized compound was also established. The main factors that influence the process of producing 6-nitro-3,4-dihydroquinazolin-4-one are identified. The process is optimized by the method of mathematical planning of the experiment. A mathematical model is drawn up. And the regression equation is calculated. A steep ascent along the response surface was carried out and optimal process conditions were found: temperature, time, quantitative ratio of the starting materials. It has been established that the main factor affecting the nitration process of 3,4-dihydroquinazolin-4-one is the temperature of 40 ºC and the reaction time is 4.5 h. Note that at a higher temperature, according to the analysis, a significant amount of dinitro derivative is formed, as a reaction byproduct.