Synthesis and antitumor evaluation of novel tetrahydrobenzo[4′,5′]thieno[3′,2′:5,6]pyrimido[1,2-<i>b</i>]isoquinoline derivatives

<p>In the present study, a novel 8,9,10,11-tetrahydro-7<i>H</i>,14<i>H</i>-benzo[4′,5′] thieno[2′,3′:4,5]-1,3-oxazino[3,2-<i>b</i>]isoquinoline-7,14-dione <b>5</b> was prepared by condensation of 2-amino-3-carbethoxy-4,5,6,7-tetrahydrobenzothiophene with homophthalic anhydride under microwave irradiation, followed by alkaline hydrolysis and cyclization using acetyl chloride. Compound <b>5</b> was further allowed to react with different nitrogen nucleophiles to get new tetrahydrobenzothienopyrimido isoquinolinone derivatives. The structures of the prepared compounds were elucidated by IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, and mass spectroscopy. The newly prepared compounds were tested <i>in vitro</i> against a panel of two human tumor cell lines, namely, hepatocellular carcinoma (liver) HepG2, and mammary gland breast MCF-7. Almost all the tested compounds showed satisfactory activity.</p>