An easy synthesis of 5-functionally substituted ethyl 4-amino- 1-aryl- pyrazolo- 3-carboxylates: interesting precursors to sildenafil analogues

• Said A. S. Ghozlan,
• Khadija O. Badahdah and
• Ismail A. Abdelhamid

Beilstein J. Org. Chem. 2007, 3, No. 15, doi:10.1186/1860-5397-3-15

• report results of our work aimed at exploring this synthetic methodology and adoption of products for the synthesis of pyrazolo[4.3-d]pyrimidines. Thus, compounds 1a-c, were prepared according to literature procedures via coupling of ethyl cyanoacetate with aromatic diazonium salts [10]. It has been