Synthesis and cytotoxic activity of carboxamide derivatives of benzo[b][1,6]naphthyridin-(5H)ones

Twenty-six new compounds were prepared and tested. Compound 2t (R = 6-Me, X = 4-FC6H4, Y = (CH2)2NMe2) at 1.8 mg kg−1 was curative against colon 38 tumors in mice.