Abstract: In this study, a series of conformationally restricted thieno [3, 2-d] pyrimidinones, thieno [3, 2-d] pyrimidines and quinazolinones was designed and synthesized with the goal of improving the biological activity as 17β-hydroxysteroid dehydrogenase type 2 inhibitors of the corresponding amidothiophene derivatives. Two moderately active compounds were discovered and this allowed the identification of the biologically active open conformer as ...
![4-Chloro-6-(4-methoxyphenyl)thieno[3,2-d]pyrimidine Structure](https://image.chemsrc.com/caspic/183/869709-83-1.png)