For structure-activity manipulations, the compound α-thiagra (3), a thiophene bioisostere of viagra®, has been prepared and its X-Ray structure determined. The crystallographic data show that the thiophene and pyrazolo[4,3-d]pyrimidone hetero-ring systems are nearly coplanar by virtue of an adequate intramolecular hydrogen-bond between the pyrimidone NH and the oxygen lone pair of the 3'-ethoxy group.
|Number of pages||10|
|Publication status||Published - Dec 1 2000|
ASJC Scopus subject areas
- Analytical Chemistry
- Organic Chemistry