N-Bromosuccinimide as an Almost Neutral Catalyst for Efficient Synthesis of Dihydropyrimidinones Under Microwave Irradiation
Hassan Hazarkhani, Babak Karimi*
*Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS),
P.O.Box 45195-159, Gava Zang, Zanjan, Iran, Email: karimi
iasbs.ac.ir
H. Hazarkhani, B. Karimi, Synthesis, 2004, 1239-1242.
DOI: 10.1055/s-2004-822348
Abstract
NBS has been used as a mild, efficient and almost neutral catalyst for the preparation of dihydropyrimidinones (DHPMs) and the corresponding thio-derivatives under microwave irradiation. A wide variety of DHPMs were synthesized in good to high yields.
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Details
The document discusses the use of N-Bromosuccinimide (NBS) as a mild, efficient, and almost neutral catalyst for synthesizing dihydropyrimidinones (DHPMs) and their thio-derivatives under microwave irradiation. DHPMs are significant due to their biological activities, including antihypertensive, antibacterial, antitumor, and anti-inflammatory properties. Traditional methods for DHPM synthesis often result in low yields, especially with substituted aromatic and aliphatic aldehydes. The study highlights that NBS, a cheap and safe reagent, can catalyze the reaction efficiently under mild conditions, providing high yields and short reaction times. The use of microwave irradiation further accelerates the reaction, making it almost complete within minutes. The document provides detailed procedures and results for various aldehydes, demonstrating the effectiveness of NBS in different reaction conditions. The study concludes that NBS is a valuable catalyst for DHPM synthesis, offering a complementary method to existing protocols with advantages such as high yields, short reaction times, and mild conditions. Further applications of NBS in organic transformations are being explored.
Key Words
Biginelli Reaction, N-bromosuccinimide, dihydropyrimidinones, microwave synthesis
ID: J66-Y2004-2070
