A facile synthesis of 2(H)-oxo-3-substituted-1-benzopyrans

936-93

Reactions of 2-chloro-4,5-diamino-6-methylpyrimidine with 1,3-diketones — Formation of new substituted purines⁺

191-194Condensation of 2-chloro-4,5-diamino-6-methylpyrimidine 1 with 1,3-diketones 2 results intermediate schiffs base 3.The latter on cyclisation yields purines 4a-e. The reaction of 1 with aromatic aldehyde is also studied

A facile synthesis of 4-oxo-1,2 , 3,4-tetrahydropyrido[3<i>'</i>,2<i>'</i>:4,5] furo[3,2-<i>d</i>]pyridines : A new tricyclic heterocyclic ring system

605-6102-Acetyl-3-amino-4-trifluoromethyl-6-substitutcdphenylfuro[2,3-b]pyridines are subjected to Claisen-Schmidth condensation with different arylaldehydes followed by intramolecular Michael type addition to obtain 4-oxo-1,2 ,3,4-tetrahydropyrido [3',2':4,5]furo[3,2-d] pyridines, a new tricyclic heterocyclic ring system of biological interest. The studies directed towards the synthesis of pyridofuropyrazoles have also been discussed

Synthesis of nove1 2,6-disubstituted-3-amino-4-trifluoromethylfuro[2,3-<i>b</i>] pyridines^†

558-564A series of novel 2-acyl or benzoyl-3-amino-4-tritluoromethyl-6-substituted furo[2,3-b]-pyridines have been synthesised from 4-tritluoromethyl-6-substituted-1,2-dihydro-2-oxo-3-pyridine carbonitrile via 2-O-phenacyl or acetonyl-3-cyano-4-tritluoromethyl-6-substituted pyridines

An Efficient Multi-component Synthesis of 6-Amino-3-methyl-4-Aryl-2,4- dihydropyrano[2,3-c]Pyrazole-5-carbonitriles

Multi-component reactions are effective in building complex molecules in a single step in a minimum amount of time and with facile isolation procedures; they have high economy1–7 and thus have become a powerful synthetic strategy in recent years.8–10 The multicomponent protocols are even more attractive when carried out in aqueous medium. Water offers several benefits, including control over exothermicity, and the isolation of products can be carried out by single phase separation technique. Pyranopyrazoles are a biologically important class of heterocyclic compounds and in particular dihydropyrano[2,3-c]pyrazoles play an essential role in promoting biological activity and represent an interesting template in medicinal chemistry. Heterocyclic compounds bearing the 4-H pyran unit have received much attention in recent years as they constitute important precursors for promising drugs.11–13 Pyrano[2,3-c]pyrazoles exhibit analgesic,14 anti-cancer,15 anti-microbial and anti-inflammatory16 activity. Furthermore dihydropyrano[2,3-c]pyrazoles show molluscidal activity17,18 and are used in a screening kit for Chk 1 kinase inhibitor activity.19,20 They also find applications as pharmaceutical ingredients and bio-degradable agrochemicals.21–29 Junek and Aigner30 first reported the synthesis of pyrano[2,3-c]pyrazole derivatives from 3-methyl-1-phenylpyrazolin-5-one and tetracyanoethylene in the presence of triethylamine. Subsequently, a number of synthetic approaches such as the use of triethylamine,31 piperazine,32 piperidine,33 N-methylmorpholine in ethanol,34 microwave irradiation,35,36 solvent-free conditions,37–39 cyclodextrins (CDs),40 different bases in water,41 γ -alumina,42 and l-proline43 have been reported for the synthesis of 6-amino-4-alkyl/aryl-3-methyl- 2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles. Recently, tetraethylammonium bromide (TEABr) has emerged as mild, water-tolerant, eco-friendly and inexpensive catalyst. To the best of our knowledge, quaternary ammonium salts, more specifically TEABr, have notbeen used as catalysts for the synthesis of pyrano[2,3-c]pyrazoles, and we decided to investigate the application of TEABr as a catalyst for the synthesis of a series of pyrazole-fused pyran derivatives via multi-component reactionsCUSATOrganic Preparations and Procedures International, 45:429–436, 201

ZrOCl₂.8H₂O as a new solid phase and recyclable catalyst for an efficient Knoevenagel condensation under solvent- free microwave irradiation conditions

1301-1303A new solid phase and recyclable catalyst for an efficient Knoevenagel condensation under solvent-free microwave irradia­tion conditions has been developed for universal applications in C-C bond formation

A facile strategy for the synthesis of highly substituted imidazole using tetrabutyl ammoniumbromide as catalyst

A simple and facile strategy for the synthesis of highly substituted imidazoles has been developed by multi-component condensation of 1,2-diketone, aldehyde, amine, and ammonium acetate in presence of tetrabutyl ammonium bromide as catalystCochin University Of Science And TechnologyRes Chem Intermed (2012) 38:359–365 DOI 10.1007/s11164-011-0352-

<span style="font-size:15.0pt;mso-bidi-font-size: 14.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-US">Synthesis and biological evaluation of novel <i style="mso-bidi-font-style:normal">N</i>1-decyl and C7- <i style="mso-bidi-font-style: normal">sec </i>amine substituted fluoroquinolones as antitubercular and anticancer agents</span>

1495-1501<span style="font-size: 9.0pt;mso-bidi-font-size:8.0pt" lang="EN-US">A series of novel <i style="mso-bidi-font-style: normal">N1-decyl and C7- sec amine substituted fluoroquinolone derivatives have been synthesized and evaluated for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain and anticancer activity have been studied against four human cancer cell lines (HeLa, MDA-MB-231, MIA PaCa and IMR32). Compounds 4 and <b style="mso-bidi-font-weight: normal">5a exhibit significant antitubercular and antiproliferative activity. The results are encouraging and indicate towards a lead molecule in a combination therapy. </span

Gadolinium (III) chloride catalyzed facile synthesis of 2-substituted benzimidazoles under solvent-free conditions

953-957A series of 2-substituted benzimidazoles have been prepared from o-diamines and 1,3-dicarbonyl compounds using Gadolinium chloride as a catalyst under solvent free condition in good yields. Gadolinium chloride has been demonstrated as a mild and efficient catalyst

A facile and single pot strategy for the synthesis of novel naphthyridine derivatives under microwave irradiation conditions using ZnCl2 as catalyst, evaluation of AChE inhibitory activity, and molecular modeling studies

A series of novel naphthyridine derivatives 3 and 4 was prepared from substituted pyridine 2 and ketones using ZnCl2 as catalyst under microwave irradiation conditions. All the compounds were evaluated for AChE inhibitory activity and promising compounds 3d, 3e, 4b, and 4g was identified. Representative compounds 3d and 3e were found to show insignificant THLE-2 liver cell viability/toxicity. The binding mode between X-ray crystal structure of human AChE and compounds was studied using molecular docking method and fitness scores were found to be in good correlation with the activity data.CUSATMed Chem Res (2012) 21:1785–1795 DOI 10.1007/s00044-011-9695-