Design, synthesis, biological evaluation and X-ray crystal structure of novel classical 6,5,6-tricyclic benzo[4,5]thieno[2,3-d]pyrimidines as dual thymidylate synthase and dihydrofolate reductase inhibitors was written by Zhang, Xin;Zhou, Xilin;Kisliuk, Roy L.;Piraino, Jennifer;Cody, Vivian;Gangjee, Aleem. And the article was included in Bioorganic & Medicinal Chemistry in 2011.Formula: C12H17NO2S The following contents are mentioned in the article:
Classical antifolates (4-7) with a tricyclic benzo[4,5]thieno[2,3-d]pyrimidine scaffold and a flexible and rigid benzoylglutamate were synthesized as dual thymidylate synthase (TS) and dihydrofolate reductase (DHFR) inhibitors. Oxidative aromatization of Et 2-amino-4-methyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate (±)-9 to Et 2-amino-4-methyl-1-benzothiophene-3-carboxylate 10 with 10% Pd/C was a key synthetic step. Compounds with 2-CH3 substituents inhibited human (h) TS (IC50 = 0.26-0.8 μM), but not hDHFR. Substitution of the 2-CH3 with a 2-NH2 increases hTS inhibition by more than 10-fold and also affords excellent hDHFR inhibition (IC50 = 0.09-0.1 μM). This study shows that the tricyclic benzo[4,5]thieno[2,3-d]pyrimidine scaffold is highly conducive to single hTS or dual hTS-hDHFR inhibition depending on the 2-position substituents. The X-ray crystal structures of 6 and 7 (I) with hDHFR reveal, for the first time, that tricyclics 6 and 7 bind with the benzo[4,5]thieno[2,3-d]pyrimidine ring in the folate binding mode with the thieno S mimicking the 4-amino of methotrexate. This study involved multiple reactions and reactants, such as Ethyl 2-amino-4-methyl-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate (cas: 95211-67-9Formula: C12H17NO2S).
Ethyl 2-amino-4-methyl-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate (cas: 95211-67-9) belongs to benzothiophene derivatives. Benzothiophene is a fused ring compound of thiophene ring and benzene ring, which is an important class of heterocycles with advantageous structures. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, and sertaconazole, and also BTCP.Formula: C12H17NO2S
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem