Synthesis of New Functionalised Derivatives of [1,2,4]triazolo[4,3-a]Pyrimidine and Pyrimido[2,1-b][1,3,5]Thiadiazine as Aromatase Inhibitors

New functionalised 3,4-dihydropyrimido[2,1-b][1,3,5]thiadiazine-6,8-(2H,7H)-dione and [1,2,4]triazolo[4,3-a]pyrimidine-5,7-(1H,6H)-dione derivatives were synthesised through the reaction of thiobarbituric acid with aromatic amines and formaldehyde and from thiobarbituric acid and hydrazonoyl halides, respectively. The structures of the target compounds were confirmed by 1 H NMR, IR and MS spectra. Moreover, the newly synthesised products were tested for their aromatase inhibition activities and the results obtained were promising compared with the drug letrozole, a non-steroidal aromatase inhibitor.