N-substituted indenoisoquinolines and syntheses thereof
N-Substituted indenoisoquinoline compounds, and pharmaceutical formulations of N-substituted indenoisoquinoline compounds are described. Also described are processes for preparing N-substituted indenoisoquinoline compounds. Also described are methods for treating cancer in mammals using the described N-substituted indenoisoquinoline compounds or pharmaceutical formulations thereof.
1. A process for preparing a compound of the formula
without isolating an intermediate product, the process comprising: reacting a compound of the formula
with a compound of the formula
and
cyclizing the intermediate product
wherein
R a represents 1-4 substituents each of which is independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted alkyl, optionally substituted alkoxy, cyano, nitro, optionally substituted alkylthio, optionally substituted alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof; or R a 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 alkyl, optionally substituted alkoxy, cyano, nitro, optionally substituted alkylthio, optionally substituted alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof;
R d represents 1-4 substituents each of which is independently selected from the group consisting of hydrogen, halo, hydroxy, optionally substituted alkyl, optionally substituted alkoxy, cyano, nitro, optionally substituted alkylthio, optionally substituted alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof; or R d 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 alkyl, optionally substituted alkoxy, cyano, nitro, optionally substituted alkylthio, optionally substituted alkylsulfonyl, carboxylic acid and derivatives thereof, and sulfonic acid and derivatives thereof.
2. The process of claim 1 wherein the cyclizing step includes one or more acids.
3. The process of claim 1 wherein R a represents a 3-nitro substituent and R d represents a 9-methoxy substituent.