The first practical approach to new pyrimido[4,5-d]pyridazines: novel chemoselective and regioselective reactions

The first practical approach to new pyrimido[4,5-d]pyridazines: novel chemoselective and regioselective reactions (13-7963MP) Arkivoc 2013 Part (iv): General Papers [pp. 323-333] Bahador Karami, Sedigheh Akrami, Saeed Khodabakhshi and S. Setareh Rahmatzadeh Full Text: PDF (325K)

Bahador Karami,* Sedigheh Akrami, Saeed Khodabakhshi, and S. Setareh Rahmatzadeh

Department of Chemistry, Yasouj University, Yasouj, Zip Code: 75918-74831 P.O.Box 353, Iran
E-mail: karami@mail.yu.ac.ir


Abstract
A new three-component condensation of aryl glyoxals, acetylacetone and urea in the presence of a
small amounts of tungstate sulfuric acid (TSA) leads to novel functionalized 5-acetyl-4-(aryloyl)-
3,4-dihydropyrimidinones which these heterocycles can undergo the Knorr condensation with
hydrazines to produce new pyrimido[4,5-d]pyridazines in good yields. These approaches are
consistent with principles of green chemistry due to some factors, such as the use of a safe and
recyclable catalyst under solvent-free conditions.

Persian miniature depicting Timur‘s campaign in India

teheran at night

Ayatollah Khomeini returns to Iran after 14 years exile on February 1, 1979.