In view of the great potential the quinazoline class of compounds offer, we started the synthesis and screening of a large number of new chemical entities with novel structural features. It has been surprisingly and unexpectedly found that quinazolines having 3- Ethynyl anilino group at the 4th position and specifically substituted alkoxy groups in the 6 and 7 positions, impart much enhanced and special anti-proliferative properties when compared to other prominent members of the quinazoline class of drugs. Also, surprisingly the compounds of this invention are much less toxic and the safety profile is exceedingly beneficial for therapeutic applications. The novel chemical entities described in this invention are designated by the general structure (I) and have not been synthesized earlier nor investigated for their therapeutic benefits and safety profile. Compund (I) is NRC-2694, when structure (A).