Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact:

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Regular issue | Vol 65, No. 8, 2005, pp.1821-1827
Published online, 1st July, 2005
DOI: 10.3987/COM-05-10398
High Throughput Synthesis of Pyrazolopyrimidines via Copper-catalysed Cyclization, and X-Ray Study

Raid J. Abdel-Jalil,* Monther Khanfar, Samer Al-Gharabli, Mustafa M. El-Abadelah, Klaus Eichele, Muhammad Usman Anwar, and Wolfgang Voelter*

*Institute of Physiological Chemistry, University of Tuebingen, Hoppe-Seyler-Srasse 4, D-72076 Tuebingen, Hoppe-Seyler-Srasse 4, D-72076 Tuebingen, Germany


A rapid and easy high-yielding synthesis of pyrazolopyrimidinones in the presensce of copper chloride is described. To fully confirm the structure of a Viagra® intermediate, the X-Ray structure of 5-(2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydropyrazolo[4,3-d]pyrimidin-7-one (2a) was determined.