Nitrophenyl-group-containing Heterocycles. Part I. Synthesis, Characterization, Anticancer Activity and Antioxidant Properties of Some New 5,6,7,8-tetrahydroisoquinolines Bearing 3(4)-nitrophenyl Group

Abstract Regioselective cyclocondensation of 2,4-diacetyl-5-hydroxy-5-methyl-3-(3-nitrophenyl/4-nitrophenyl)cyclohexanones 1a,b with cyanothioacetamide fforded the corresponiing 7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydro-soquinoline-3(2H)-thiones 2a,b in 93-96%. Reaction of compounds 2a,b ethyl iodide, 2-chloroacetamide or N-(naphthalen-1-yl)-2-chloroacetamide (5) in the presence of sodium acetate gave the corresponding p(5,6,7,8-tetrahydroisoquinolin-3-yl)thio derivatives 3a,b, 4a,b and 6a,b. In a similar manner, reaction of a,b with other N-aryl-2-chloroacetamides 7a-d gave 2-[(7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydroisoquinolin-3-yl)thio]-N-arylacetamides (8a-g). On heating of compounds 8a-e in ethanol containing anhydrous sodium carbonate, they converted into 7-acetyl-1-amino-N-aryl-5,8-dimethyl-8-hydroxy-6-(3-nitrophenyl/4-nitrophenyl)-6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamides 9a-e. Structural formulae of all synthesized compounds were characterized on the basis of their spectroscopic data. Also, the applications of most synthesized isoquinolines as anticancer and as antioxidant agents have been carried out and the obtained results are reported herein.