The present invention relates to a 6,7-dihydrobenzimidazo[1,2-c]quinazolin-6-one carboxylic acid and its esters of the general structural formula (I), and provides a method for their synthesis (I) where R and each R′ are selected independently from the list comprising —H—CH3, —C2H5, —C3H7, -iso-C3H7, —CH2CH2CH2CH3, —CH(CH3)CH2CH3, —CH2CH(CH3)CH3 and —C(CH3)3; n is 1, 2, 3 or 4; Y is a substituent selected from the list comprising —CH3, —C2H5, —NO2, —Cl, —Br, —F, —CF3, —CN, —OH, —OCH3, —OC2H5, —OCOCH3, —OCN, —SCN, —NH2, —NHCOCH3; and z is 0, 1, 2, 3 or 4.