Microsoft Word - Research-Paper-5

Abstract: We have developed an efficient protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by the reaction of isatoic anhydride, amine and aldehyde mediated by cyanuric chloride (1,3,5 trichloro triazine; TCT) in good to excellent yield. The reaction allows rapid cyclization and provides a new and useful strategy for the construction of N-heterocycles

Cyanuric Chloride Catalyzed Mild Protocol for Synthesis of Biologically Active Dihydro/Spiro Quinazolinones and Quinazolinone-glycoconjugates

We have developed an efficient cyanuric chloride (2,4,6-trichloro-1,3,5-triazine, TCT) catalyzed approach for the synthesis of 2,3-dihydroquinazolin-4­(1<i>H</i>)-one (<b>3a</b>–<b>3x</b>), 2-spiroquinazolinone (<b>5</b>, <b>7</b>), and glycoconjugates of 2,3-dihydroquinazolin-4­(1<i>H</i>)-one (<b>10a</b>, <b>10b</b>) derivatives. The reaction allows rapid cyclization (8–20 min) with 10 mol % cyanuric chloride to give skeletal complexity in good to excellent yield. We believe that this novel procedure may open the door for the easy generation of new and bioactive quinazolinones

A Ligand-Free Pd-Catalyzed Cascade Reaction: An Access to the Highly Diverse Isoquinolin-1(2<i>H</i>)-one Derivatives via Isocyanide and Ugi-MCR Synthesized Amide Precursors

A novel ligand-free palladium-catalyzed cascade reaction for the synthesis of highly diverse isoquinolin-1(2<i>H</i>)-one derivatives from isocyanide and amide precursors synthesized by Ugi-MCR has been developed. A broad variety of acids, amines, and isocyanides were used as starting materials for Ugi-MCR leading to various amide precursors, which in turn provided entry into diverse isoquinolin-1(2<i>H</i>)-one derivatives. The reaction proceeds through tandem isocyanide insertion with intramolecular cyclization followed by a Mazurciewitcz–Ganesan type sequence to provide isoquinoline-1(2<i>H</i>)-one derivatives in moderate to good yields

Access to Indole- And Pyrrole-Fused Diketopiperazines via Tandem Ugi-4CR/Intramolecular Cyclization and Its Regioselective Ring-Opening by Intermolecular Transamidation

An efficient approach for the synthesis of indole- and pyrrole-fused diketopiperazines has been developed. This protocol involves the Ugi four-component reaction (U-4CR) followed by an intramolecular cyclization of the Ugi products at room temperature to afford the desired products in good to excellent yields. In addition, it is interesting to report the subsequent regioselective ring-opening of diketopiperazine unit occurring via an intermolecular transamidation reaction under mild condition, resulting in the formation of highly functionalized indole-2-carboxamides and pyrrole-2-carboxamides

Discovery of a New Class of Natural Product-Inspired Quinazolinone Hybrid as Potent Antileishmanial agents

The high potential of quinazolinone containing natural products and their derivatives in medicinal chemistry led us to discover four novel series of 53 compounds of quinazolinone based on the concept of molecular hybridization. Most of the synthesized analogues exhibited potent leishmanicidal activity against intracellular amastigotes (IC₅₀ from 0.65 ± 0.2 to 7.76 ± 2.1 μM) as compared to miltefosine (IC₅₀ = 8.4 ± 2.1 μM) and nontoxic toward the J-774A.1 cell line and Vero cells. Moreover, activation of Th1 type and suppression of Th2 type immune responses and induction in nitric oxide generation proved that <b>8a</b> and <b>8g</b> induce murine macrophages to prevent survival of parasites. Compounds <b>8a</b> and <b>8g</b> exhibited significant in vivo inhibition of parasite 73.15 ± 12.69% and 80.93 ± 10.50% against Leishmania donovani/hamster model. Our results indicate that compounds <b>8a</b>, <b>8g</b>, and <b>9f</b> represent a new structural lead for this serious and neglected disease