this method is performed similarly to the sequence shown in scheme 8 except that 2 3 bromo phenyl ethylamine is used as the starting material scheme 9 above depicts a method for the synthesis of dihydro 1 u2032 h 1 2 u2032 biisoquinolinyl compounds according to this method in what is known as palladium catalyzed amination reaction 1 chloro 6 7 dimethoxy isoquinoline is heated with the appropriate substituted tetrahydroisoquinoline in the presence of palladium acetate and an appropriate ligand such as binap suitable solvents include but are not limited to benzene toluene and xylene and effective temperatures range from room temperature to 160 u00b0 c with 80 u00b0 c to 120 u00b0 c being particularly effective this amination reaction can be accomplished through a variety of other coupling methods hartwig j f palladium catalyzed amination of aryl halides mechanism and rational catalyst design synlett 1996 p 329 340 substituted tetrahydroisoquinolines can be prepared several well known methods three of these methods are shown in schemes 10 11 and 12 scheme 10 illustrates a method for their formation via catalytic hydrogenation of the corresponding substituted isoquinoline the hydrogenation reaction is commonly known to those skilled in the art scheme 11 illustrates another literature route to substituted tetrahydroisoquinolines 1 according to this method a benzylic aldehyde or ketone is combined with an alpha amino acid ester in a well known reductive amination reaction the resultant benzylamine is induced to cyclize via treatment with a strong acid such as trifluoromethanesulfonic or sulfuric acid to give a substituted tetrahydroisoquinoline product possessing a 4 oxo substituent this oxo substituent can be retained or may be reduced to the corresponding hydroxyl compound via hydrogenation catalyzed by.