6,7-dialkoxy quinazoline derivatives and methods of treating drug resistant and other tumors

Abstract

Methods of inhibiting a receptor tyrosine kinase in a subject in need thereof. Methods of inhibiting the growth of a tumor cell in a subject in need thereof. Methods of treating pancreatic cancer in a subject in need of treatment for pancreatic cancer. Methods of treating HER2 positive breast cancer in a subject in need of treatment for HER2 positive breast cancer. Methods of treating drug resistant non-small cell lung cancer in a subject in need of treatment for drug resistant non-small cell lung cancer. Each of these methods can include administering to the subject an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof.

1 .- 52 . (canceled) 
     
     
         53 . A method of treating pancreatic cancer in a subject in need thereof, the method comprising:
 administering to the subject an effective amount of a compound of formula (IA)   
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof 
       
     
     
         54 . The method of claim  3 , wherein the pharmaceutically acceptable salt is a monohydrochloride, a dihydrochloride, or a mixture thereof.