Abstract: Compounds of formula (I) in which: R1 is: R2 is —CH3 or —CH2CH3; or a pharmaceutically acceptable salt thereof. Pharmaceutical compositions including the compound of formula (I) and a pharmaceutically acceptable carrier. Processes for preparing the compound of formula (I). 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.

Abstract: Methods employing and uses of a compound of formula (I) in inhibiting the growth of a tumor cell in a subject in need thereof. Methods employing and uses of a compound of formula (I) in treating pancreatic cancer in a subject in need of treatment for pancreatic cancer. Methods employing and uses of a compound of formula (I) in treating HER-2 positive breast cancer in a subject in need of treatment for HER-2 positive breast cancer. Methods employing and uses of a compound of formula (I) in 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.