Stat3 pathway inhibitors and cancer stem cell inhibitors

A pharmaceutical composition comprising a compound of formula IV,

• or an enantiomer, diastereomer, tautomer, or pharmaceutically acceptable salt thereof, wherein the symbols have the following meanings and are, for each occurrence, independently selected:
• X is O or S;
• R1 is hydrogen, halogen, cyano, nitro, CF3, OCF3, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, aryl or substituted aryl, ORa, or SRa;
• R7 is hydrogen, halogen, cyano, nitro, CF3, OCF3, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, aryl or substituted aryl, ORa, or SRa;
• R8 is hydrogen, substituted alkyl, cycloalkyl or substituted cycloalkyl, aryl or substituted aryl, alkylaryl or substituted alkylaryl;
• R9 and R10 are each independently hydrogen, alkyl or substituted alkyl, cycloalkyl or substituted cycloalkyl, alkylaryl or substituted alkylaryl, alkylheteroaryl or substituted alkylheteroaryl;
• or R9 and R10 together with the carbon to which they are bonded optionally form cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle;
• Ra, is hydrogen, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, or aryl or substituted aryl;
• and
• n is 1-4;
• and a pharmaceutically-acceptable excipient, carrier, or diluent.

A method of treating a cancer in a subject, the method comprising administering the subject a therapeutically effective amount of a compound of formula IV,

• or an enantiomer, diastereomer, tautomer, or pharmaceutically acceptable salt thereof, wherein the symbols have the following meanings and are, for each occurrence, independently selected:
• X is O or S;
• R1 is hydrogen, halogen, cyano, nitro, CF3, OCF3, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, aryl or substituted aryl, ORa, or SRa;
• R7 is hydrogen, halogen, cyano, nitro, CF3, OCF3, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, aryl or substituted aryl, ORa, or SRa;
• R8 is hydrogen, substituted alkyl, cycloalkyl or substituted cycloalkyl, aryl or substituted aryl, alkylaryl or substituted alkylaryl;
• R9 and R10 are each independently hydrogen, alkyl or substituted alkyl, cycloalkyl or substituted cycloalkyl, alkylaryl or substituted alkylaryl, alkylheteroaryl or substituted alkylheteroaryl;
• or R9 and R10 together with the carbon to which they are bonded optionally form cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle;
• Ra, is hydrogen, alkyl or substituted alkyl, alkenyl or substituted alkenyl, alkynyl or substituted alkynyl, cycloalkyl or substituted cycloalkyl, cycloalkenyl or substituted cycloalkenyl, heterocycle or substituted heterocycle, or aryl or substituted aryl;
• and
• n is 1-4;
• and
• wherein the cancer is selected from the group consisting of breast cancer, lung cancer, cervical cancer, colon cancer, prostate cancer, liver cancer, head and neck cancer, and pancreatic cancer.