DR ANTHONY MELVIN CRASTO,WorldDrugTracker, helping millions, A 90 % paralysed man in action for you, I am suffering from transverse mylitis and bound to a wheel chair, With death on the horizon, nothing will not stop me except God
DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution
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Wednesday, 26 December 2012

Iron-Catalyzed Synthesis of 2-Arylbenzo[b]furans




Iron-Catalyzed Synthesis of 2-Arylbenzo[b]furans

Synthetic Communications

Volume 43, Issue 6, 2013


Jianguo YangGuodong Shen & Dingben Chen
pages 837-847

DOI:10.1080/00397911.2011.610550
http://www.tandfonline.com/doi/abs/10.1080/00397911.2011.610550
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Abstract

An iron-catalyzed procedure was employed to achieve both the Sonogashira cross-coupling and intramolecular o-arylation of o-iodophenols and aryl acetylenes/1-substituted-2-trimethylsilyl acetylenes. A variety of 2-arylbenzo[b]furans were synthesized in moderate to good yields under the catalysis of 5% FeCl3 and 10% 1,10-phenanthroline.

Monday, 3 December 2012

Sodium dodecyl sulfate in water: greener approach for the synthesis of quinoxaline derivatives





A simple energy efficient one step SDS catalysed 0.03% greener method for the synthesis of quinoxaline der using water as solvent is described

A mild and efficient synthetic method has been developed for the preparation of biologically important quinoxalines in excellent yield from relatively safe precursor α-bromoketones and 1,2-diamines using catalytic amount of micellar sodium dodecyl sulfate in water at ambient temperature. The method is also found effective for the introduction of quinoxaline moiety into the ring A of pentacyclic triterpenoid, friedelin. Ambient reaction conditions, renewable catalytic condition, inherently safer chemistry, excellent product yields, and water as a reaction medium display both economic and environmental advantages.

General procedure for quinoxalines

In a typical experimental procedure, o-phenlylenediamine (1 mmol) and α-bromoketone (1 mmol) in 1:1 molar ratios was taken in a 50 ml round bottom flask. To this water (3 ml) and 10 mg (0.03 mol%) SDS was admixed. The reaction mixture was then allowed to stir with magnetic spinning bar at room temperature. After the completion of the reaction (checked by TLC), the residue was filtered, washed with water, dried and finally recrystallized from methanol. The desired pure product was characterized by spectral (IR, 1H- and 13C-NMR) data and compared to those reported in literature.

Green Chemistry Letters and Reviews

http://www.tandfonline.com/doi/full/10.1080/17518253.2012.703245

DOI:
10.1080/17518253.2012.703245
Pranab Ghosh & Amitava Mandal
 Department of Chemistry, University of North Bengal, Darjeeling, West Bengal, 734 013, India

Sodium dodecyl sulfate in water: greener approach for the synthesis of quinoxaline derivatives

Quinoxalines are ubiquitous heterocyclic units in pharmaceuticals and bioactive natural products 1–4. They are used as pharmaceuticals and antibiotics such as echinomycin, levomycin, and actinoleutin which are known to inhibit the growth of Gram-positive bacteria and are also active against various transplantable tumors 1–3. Antitumoral properties of quinoxaline compounds have also been investigated


Saturday, 24 November 2012

Continuous Flow Synthesis of Organic Electronic Materials – Case Studies in Methodology Translation and Scale-up



 Continuous Flow Synthesis of Organic Electronic Materials – Case Studies in Methodology Translation and Scale-up
 Helga Seyler , Wallace W. H. Wong et al

Australian Journal of Chemistry - http://dx.doi.org/10.1071/CH12406
Submitted: 1 September 2012  Accepted: 3 October 2012   Published online: 19 November 2012
 
Continuous flow chemistry was applied for the derivatization of alkylthiophene building blocks. The advantages of reaction automation and scale-up were demonstrated for selective lithiation-borylation and Knoevenagel condensation of thiophene derivatives. These synthetic approaches allow facile and rapid access to monomer and dyes for organic electronic applications.
read more at
 http://www.publish.csiro.au/paper/CH12406.htm     copy paste link

Wednesday, 21 November 2012

Reduction of Sulfonylimines with Raney Nickel




Reduction of Sulfonylimines with Raney Nickel

José Luis García Ruano, José A. Fernández-Salas, M. Carmen Maestro & Alejandro Parra
pages 198-207

  • DOI:10.1080/00397911.2011.594974
  • http://www.tandfonline.com/doi/abs/10.1080/00397911.2011.594974   copy paste link

Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry,Volume 43, Issue 2, 2013  advance article                   

Raney-Ni/EtOH reduction of different N-sulfonylimines provides a new entry for synthesizing sulfonamides in good yields under mild conditions. This protocol, which does not require additional hydrogen, constitutes a cheap, safe, and easy-to-handle alternative procedure to prepare α-branched sulfonamides.

Synthesis of Enantiomerically Enriched α-Bromonitriles from Amino Acids



Synthesis of Enantiomerically Enriched α-Bromonitriles from Amino Acids

Najeh Tka, Jamil Kraïem & Béchir Ben Hassine
pages 735-743, DOI:10.1080/00397911.2011.608142

http://www.tandfonline.com/doi/abs/10.1080/00397911.2011.608142
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Two methods were investigated for the preparation of six chiral α-bromonitriles with different optic purities. The nitrous deamination of amino acids gives α-bromoacids, which react with chlorosulfonyl isocyanate followed by triethylamine to afford α-bromonitriles with moderate enantiomeric excess. However, the dehydration of corresponding α-bromoamids using thionyl chloride gives α-bromonitriles with good enantiomeric excess up to 94%. The use of phosphoryl chloride instead of thionyl chloride results in more than 30% racemization as determined by high-performance liquid chromatograpic analysis.

Sunday, 18 November 2012

Synthesis of Quinolines Using Nano-Flake ZnO as a New Catalyst under Solvent-Free Conditions

J. Iran. Chem. Soc., Vol. 8, No. Suppl., February 2011, pp. S119-S128.
http://www.ics-ir.org/jics/archive/v8/S1/Articles/pdf/JICS-8-S1-Article-13.pdf
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Synthesis of Quinolines Using Nano-Flake ZnO as a New Catalyst under Solvent-Free Conditions


M. Hosseini-Sarvari, Department of Chemistry, College of Science, Shiraz University, Shiraz, 71454, Iran

     Catalytic activity of nano-flake ZnO for synthesis of quinoline derivatives and their related polyheterocycles under solvent-free conditions has been studied. Nano-flake ZnO has been successfully synthesized by conventional heating of a solution approach using ZnOAc.2H2O and Urea. This method is simple, cost-effective, and environmentally benign and the catalyst can be reused for several times.






Thursday, 15 November 2012

Diversity Oriented Syntheses of Conventional Heterocycles by Smart Multi Component Reactions (MCRs) of the Last Decade



abstract graphic


Molecules 2012, 17(1), 1074-1102; doi:10.3390/molecules17011074
http://www.mdpi.com/1420-3049/17/1/1074   copy paste on browser

 A collection of smart multicomponent reactions (MCRs) with continuative post condensation cyclizations (PCCs) is presented to construct conventional three- to seven-membered heterocyclic compounds in diversity oriented syntheses (DOS). These will provide a high degree of applying economical and ecological advantages as well as of practicability. Water, ionic liquids, and solvent-less syntheses as well as use of various forms of energy as microwave and ultrasonic irradiation are examined and discussed.

Friday, 2 November 2012

Progress in Microwave-Aided Chemical Synthesis

Progress in Microwave-Aided Chemical Synthesis
Hani Mutlak A. Hassan A B, Steve Harakeh A, Kaltoom A. Sakkaf A and Iuliana Denetiu A

A King Fahd Medical Research Centre, King Abdulaziz University, PO Box 80216, Jeddah 21589, Kingdom of Saudi Arabia. B Corresponding author. Email:
hmahassan@kau.edu.sa


Australian Journal of Chemistry - http://dx.doi.org/10.1071/CH12366
Submitted: 5 August 2012  Accepted: 16 September 2012   Published online: 29 October 2012
 LINK IS
 http://www.publish.csiro.au/paper/CH12366.htm



The continuing use of microwave (µwave) energy in chemical synthesis has been impressive over the past decade, with many reports incorporating µwave-based reactions. Two of the major benefits of using µwave heating are the remarkable decrease in reaction times and often high yield of products in comparison with classical heating, an ideal technology for synthetic chemists. Herein, we highlight some exciting examples of its recent utility in organic, medicinal, and natural product synthetic endeavours.




Saturday, 6 October 2012

Enabling integrated biorefineries through high-yield conversion of fractionated pentosans into furfural


Green Chem., 2012, Advance Article
DOI: 10.1039/C2GC35759C, Paper 

 http://pubs.rsc.org/en/content/articlelanding/2012/gc/c2gc35759c

Graphical abstract: Enabling integrated biorefineries through high-yield conversion of fractionated pentosans into furfural

 Batch reactive distillation of biomass hydrolysates was employed to produce furfural in high yield using an entirely aqueous acid-catalyzed process. 

 Dilute aqueous solutions of furfural were produced in high yield from biomass hydrolysates using an acid-catalyzed batch reactive distillation process that separated the vapor phase from the aqueous reactant medium. Hot water hydrolysates from hybrid poplar, miscanthus, switchgrass and corn stover were dehydrated using sulfuric acid. The vapor fraction from the reactor was condensed to produce furfural in excess of 85% of the theoretical yield based on total pentose. Using xylose as the model compound, and temperature and acid concentration as the variables, the process conditions were optimized by the construction of a three-level statistical model. Hot water hydrolysis of biomass provided with a cellulose-rich solid fraction which has potential for conversion into pulp or cellulosic ethanol, while the liquid fraction, rich in hemicellulose sugars, was converted into furfural. Fractionating the biomass allows for exploration of the concept of the integrated biorefinery where the hemicellulose sugars are not underutilized or encountered as potential inhibitors during microbial conversions of the solid stream, but are converted into furfural, a valuable chemical precursor. The availability of the cellulose fraction for further conversion into pulp or ethanol gives the current process a major advantage over the conventional batch process used in industry, where theoretical yields do not exceed 45–50% with the conspicuous absence of a usable cellulose stream.

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