The previously mentioned 6,8-dibromo-2-(3,4-dichlorophenyl)quinazolin-4(3H)-one 1 was constructed and utilized as a building block for the synthesis of quinazolinone derivatives 2-11 with significant expected medicinal efficiency . The reaction of the hydrazinyl derivative 9 with carbon disulfide led to the formation of 7,9-dibromo-5-(3,4-dichlorophenyl)-[1,2,4]triazolo[4,3-c]quinazoline-3(2H)-thione 12. From the compound 6,8-dibromo-2-(3,4-dichlorophenyl)quinazoline-4(3H)thione 8 came the quinazolinone derivatives 13-16. Physical and chemical methods were used to characterize the constructed products.