By condensation of 7-(4-bromobutoxy)-1,2,3,4-tetrahydroquinolin-2-one (I) with 1-(2,3-dichlorophenyl)piperazine (II) by means of NaI and triethylamine in refluxing acetonitrile.
The condensation of 7-hydroxy-1,2,3,4-tetrahydroquinolin-2-one (I) with 1,4-dibromobutane (II) by means of K2CO3 in hot DMF gives 7-(4-bromobutoxy)-1,2,3,4-tetrahydroquinolin-2-one (III), which is then condensed with 1-(2,3-dichlorophenyl)piperazine (IV) by means of NaI and triethylamine in refluxing acetonitrile.