Abstract: The present invention relates to a process for producing a 4-quinolone derivative, comprising allowing an o-aminoacetophenone derivative to react with a formic acid in an aprotic solvent in the presence of a suitable base, and adding a protic solvent to the reaction mixture. This is a simple process for producing 4-quinolone derivatives, applicable to large-scale commercial production.

Abstract: The present invention relates to novel quinoline derivatives and quinazoline derivatives represented by the following formula (I): ##STR1## [wherein R.sub.1 and R.sub.2 are each independently H or C.sub.1 -C.sub.4 -alkyl, or R.sub.1 and R.sub.2 together form C.sub.1 -C.sub.3 -alkylene, X is O, S or CH.sub.2, W is CH or N, and Q is a substituted aryl group or substituted heteroaryl group] and their pharmaceutically acceptable salts, having platelet-derived growth factor receptor autophosphorylation inhibitory activity, to pharmaceutical compositions containing these compounds, and to methods for the treatment of diseases associated with abnormal cell growth such as tumors.