Synthesis and use of dual tyrosyl-DNA phosphodiesterase I (Tdp1)—topoisomerase I (Top1) inhibitors

A compound of the formula

• or a pharmaceutically acceptable salt thereof,
• wherein:
• n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, or 12,
• Ra represents 1-4 substituents each of which is independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted (1-4C)alkyl, optionally substituted (1-4C)alkoxy, cyano, nitro, optionally substituted alkylthio, optionally substituted alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof;
• or Ra represents 2-4 substituents where 2 of said substituents are adjacent substituents and are taken together with the attached carbons to form an optionally substituted heterocycle, and where any remaining substituents are each independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted (1-4C)alkyl, optionally substituted (1-4C)alkoxy, cyano, nitro, optionally substituted (1-4C)alkylthio, optionally substituted (1-4C)alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof;
• and
• Rd represents 1-4 substituents each of which is independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted (1-4C)alkyl, optionally substituted (1-4C)alkoxy, cyano, nitro, optionally substituted (1-4C)alkylthio, optionally substituted (1-4C)alkylsulfonyl, phenyl (which may bear one or more amino, hydroxyl, halo, thiol, (1-6C)alkyl or halo(1-6C)alkyl substituents), carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof;
• or Rd represents 2-4 substituents where 2 of said substituents are adjacent substituents and are taken together with the attached carbons to form an optionally substituted heterocycle, and where any remaining substituents are each independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted (1-4C)alkyl, optionally substituted (1-4C)alkoxy, cyano, nitro, optionally substituted (1-4C)alkylthio, optionally substituted (1-4C)alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof;
• RS is (1-6C)alkyl, (3-7C)cycloalkyl or phenyl, which phenyl may bear one or more amino, hydroxyl, halo, thiol, (1-6C)alkyl or halo(1-6C)alkyl substituents.

A compound of the formula

• or a pharmaceutically acceptable salt thereof,
• wherein:
• RT is dimethylamino, Ra is 3-cyano and Rd is 8,9-methylenedioxy;
• or
• RT is 4-morpholinyl, Ra is 3-cyano and Rd is hydrogen;
• or
• RT is imidazolyl, Ra is 3-cyano and Rd is hydrogen.