Synthesis, Crystal Structure and Antitumor Activity of 6,7,8-Trimethoxy-1-(4-methoxy-3-nitrophenyl)-4- (pyridin-4-ylmethyl)-3,4-dihydroisoquinoline

A novel class of 3,4-dihydroisoquinolines (7a～e) was designed, synthesized and characterized by IR, NMR and ESI-MS. The crystal structure of compound 7a (6,7,8-trime- thoxy-1-(4-methoxy-3-nitrophenyl)-4-(pyridin-4-methyl)-3,4-dihydroisoquinoline, C25H25N3O6, Mr=463.48) was determined by X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/n with a=12.074(5), b=12.896(6), c=15.450(7), β=105.846(5)°, V=2314.4(17) 3, Z=4, Dc=1.330 Mg/m3, μ(MoKα)=0.096 mm-1, F(000)=976, S=0.991, the final R=0.0467 and wR=0.1231 for 4545 unique reflections (Rint=0.0656) with 3117 observed ones. The bioassay showed that compounds 7a～e exhibit moderate antitumor activities in vitro.