“…13 CB3717, pemetrexed, raltitrexed and plevitrexed are quinazoline based folic acid TS inhibitors for the treatment of various cancers. 14 Previous studies have reported that incorporation of different heterocycles in the skeleton has shown significant inhibition of TS. For example, derivatives containing pyrimidine-indole, 15,16 N -phenyl-(2,4-dihydroxy pyrimidine-5-sulfonamido)phenyl urea, 17 pyrrolo-pyrimidine, 18–20 cyanopyrimidine, 21 benzothiazole, 22 phenolnaphthalein 23 and thiouracil 24 displayed promising inhibition of TS.…”