Friday 24 May 2013

A new method for producing clean hydrogen



TEM_image_Au-a-Fe2O3_catalyst






Duke University engineers have developed a novel method for producing clean hydrogen, which could prove essential to weaning society off of fossil fuels and their environmental implications. While hydrogen is ubiquitous in the environment, producing and collecting molecular hydrogen for transportation and industrial uses is expensive and complicated. Just as importantly, a byproduct of most … more…

Thursday 23 May 2013

World Drug Tracker: Scientists sequence genome of ‘sacred lotus,’ may ...

World Drug Tracker: Scientists sequence genome of ‘sacred lotus,’ may ...: Scientists sequence genome of ‘sacred lotus,’ may hold anti-aging secrets A team of 70 scientists from the U.S., China, Austral...

One-Pot Method for Regioselective Bromin­ation and Sequential Carbon–Carbon Bond-Forming Reactions of Allylic Alcohol Derivatives

One-Pot Method for Regioselective Bromin­ation and Sequential Carbon–Carbon Bond-Forming Reactions of Allylic Alcohol Derivatives
European Journal of Organic Chemistry Noriki Kutsumura, Yusuke Matsubara, Kentaro Niwa, Ai Ito and Takao Saito
DOI: 10.1002/ejoc.201300173

Thumbnail image of graphical abstract



Di- or trisubstituted olefins were synthesized in high yields with excellent regio- and cis–trans selectivities in one-pot reactions, including a regioselective DBU-promoted trans HBr elimination. This one-pot methodology could become a straightforward transformation of “straight” alkenes into “Y-shaped” alkenes.


An efficient one-pot method for the regioselective bromination of allylic alcohol derivatives (two-step reaction sequence) followed by Sonogashira, Negishi, or Suzuki–Miyaura coupling reactions in the same reaction vessel (three-step reaction sequence) has been developed. The key reaction in these one-pot systems is the regioselective DBU-promoted trans HBr elimination of vicinal dibromides bearing an adjacent O-functional group.

Synthetic Uses of Ammonia in Transition-Metal Catalysis

European Journal of Organic Chemistry


Jinho Kim, Hyun Jin Kim and Sukbok Chang
DOI: 10.1002/ejoc.201300164
Thumbnail image of graphical abstract

Although ammonia (NH3) is a cheap, abundant, and readily available nitrogen source, it has rarely been used in transition-metal catalysis, due to several obstacles. However, significant advances in the metal-mediated utilization of ammonia have been made recently. This review presents the most recent examples in metal-mediated amination and other relevant reactions with ammonia or ammonium salts.
http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201300164/abstract

Ammonia (NH3) is a cheap, abundant, and readily available nitrogen source, being one of the chemicals produced in the greatest quantities. Whereas ammonia is utilized mainly as a feedstock for the production of fertilizers, it is also employed in industry as a component of various nitrogen-containing compounds. In metal catalysis, in contrast, ammonia has been used only with limited success, due to several difficulties such as generation of stable Lewis acid-base adducts, facile ligand exchange for ammonia in active metal complexes, a propensity towards undesired second transformations of initially formed species, and the requirement for special equipment to run the reactions. Despite these obstacles, the direct use of ammonia in catalysis has continuously attracted great interest, leading recently to significant progress. Whereas liquid or gaseous ammonia were most commonly employed in the past, under harsh conditions, notable catalytic reactions using easy-to-handle ammonium salts under milder and more convenient conditions have now been developed. In this review we briefly describe the most recent examples of transition-metal-catalyzed reactions using ammonia or ammonium salts.

Friday 17 May 2013

BASF plans production of butanediol from renewable feedstock using Genomatica technology

Large Scale Commercial Production of Renewable Butanediol

BASF plans production of butanediol from renewable feedstock using Genomatica technology




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Evonik has started basic engineering for a production plant for precipitated silica in Brazil

Evonik Plans New Silica Plant in Brazil

Evonik has started basic engineering for a production plant for precipitated silica in Brazil




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Even at low temperatures, platinum nanoparticles on a support catalyze breakdown of ethylene

Catalyst Keeps Fruit Fresh Longer

Even at low temperatures, platinum nanoparticles on a support catalyze breakdown of ethylene




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A versatile synthesis of various propiolic acid derivatives by using cesium fluoride has been developed

16 May 2013

Proper Path to Propiolic Acids

A versatile synthesis of various propiolic acid derivatives by using cesium fluoride has been developed




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Friday 10 May 2013

Full-size image (2 K)

Sweet Route to Steviamine

 

 



A concise synthesis of steviamine and three of its analogues is reported before testing for glycosidase inhibition

Read more at chemistry views


Replacing DEAD with recyclable reagents in the Mitsunobu reaction may lead to it being used for larger-scale industrial processes

Replacing a DEAD, Middle-aged Reagent



Replacing DEAD with recyclable reagents in the Mitsunobu reaction may lead to it being used for larger-scale industrial processes
Read more
at chemistryviews by David Bradley
http://www.chemistryviews.org/details/ezine/4634311/Replacing_a_DEAD_Middle-aged_Reagent.html


The Mitsunobu reaction is an organic reaction that converts an alcohol into a variety of functional groups, such as an ester, using triphenylphosphine and an azodicarboxylate such as diethyl azodicarboxylate (DEAD) or diisopropyl azodicarboxylate (DIAD) The alcohol undergoes an inversion of stereochemistry. It was discovered by Oyo Mitsunobu (1934–2003).
The Mitsunobu reaction





07 May 2013

Thursday 9 May 2013

An Improved and Efficient Process for the Production of Donepezil Hydrochloride: Substitution of Sodium Hydroxide for n-Butyl Lithium via Phase Transfer Catalysis

An Improved and Efficient Process for the Production of Donepezil Hydrochloride: Substitution of Sodium Hydroxide for n-Butyl Lithium via Phase Transfer Catalysis

Org. Process Res. Dev., 2008, 12 (4), pp 731–735
 
Publication Date (Web): May 30, 2008 (Article)
DOI: 10.1021/op800066m
 
 A simple, efficient and highly economic process for the production of donepezil hydrochloride (1), an anti-Alzheimer drug is reported. The process relies upon improved and large-scale synthesis of a key intermediate: 1-benzylpiperidine-4-carboxaldehyde (2), and the introduction of operationally simple chemistry at the penultimate stage wherein 2 is reacted with 5,6-dimethoxy indanone (3) in the presence of sodium hydroxide and a phase transfer catalyst (PTC) in a biphasic solvent to furnish the intermediate 4, which is reduced and directly treated with hydrochloric acid to furnish highly pure donepezil hydrochloride with desired polymorphic form. The improved process provides donepezil hydrochloride at considerably lower cost and allows the omission of hazardous chemicals.
 
 
Figure

Synthesis of Donepezil Hydrochloride via Chemoselective Hydrogenation

Figure

Synthesis of Donepezil Hydrochloride via Chemoselective Hydrogenation

 Org. Process Res. Development

Sterling Biotech Limited, Jambusar State Highway, Village Masar 391421, Taluka, Padra, Distt: Vadodara Gujarat India
 
Articles ASAP (As Soon As Publishable)
Publication Date (Web): April 9, 2013 (Article)
DOI: 10.1021/op400007p
 
 A simple and highly chemoselective and cost-effective process for the synthesis of Donepezil 1 has been developed for commercial production. In the process, the exocyclic double bond is mainly targeted for catalytic hydrogenation in the presence of an N-benzyl group using sulfur, nitrogen, and phosphorous catalyst modifiers. In some cases, catalytic hydrogenation with Pd on charcoal also produced an undesired side product along with the main product due to over reduction. Removal of these impurities by crystallization, column chromatography, or other means of purification makes the process tedious and lengthy, and sometimes it is difficult to achieve the impurity limit as per International Conference on Harmonisation (ICH) guidelines for active pharmaceutical ingredients. In the present investigation we report the synthesis of Donepezil 1 in pure form wherein the debenzyl impurity is within the acceptable limits.

Wednesday 8 May 2013

Aesica, University of Nottingham to develop novel drug synthesis method

University of Nottingham arms.png

Aesica, University of Nottingham to develop novel drug synthesis method
Aesica, a global contract manufacturing organisation (CMO), has announced a partnership with the UK's University of Nottingham to explore the development of alternative methods in amide bond synthesis
read at
http://www.pharmaceutical-technology.com/news/newsaesica-university-of-nottingham-to-develop-novel-drug-synthesis-method

Tuesday 7 May 2013

Copper-Mediated Cyanation of Aryl Halides by Activation of Benzyl Cyanide as the Cyanide Source

 

Cyanation Reactions

Copper-Mediated Cyanation of Aryl Halides by Activation of Benzyl Cyanide as the Cyanide SourceQiaodong Wen, Jisong Jin, Yuncai Mei, Ping Lu and Yanguang Wang
Article first published online: 6 MAY 2013 | DOI: 10.1002/ejoc.201300052

European Journal of Organic Chemistry

 


Thumbnail image of graphical abstract

An efficient, copper-mediated cascade synthesis of aryl nitriles from aryl halides using benzyl cyanide as the cyanide source is described. Compared with traditional copper-mediated cyanation reactions, this approach effectively avoided the use of toxic MCN and low soluble reagents. Furthermore, C–H oxidation and C–CN cleavage are proposed to be involved in this cascade process.



Aryl nitriles were efficiently synthesized through copper-mediated cyanation of aryl halides using benzyl cyanide as the cyanide source. Aryl halides with various substituents on the aromatic ring afforded the corresponding aryl nitriles in 32–97 % yields (25 examples). This reaction could also be carried on a gram scale by using commercially available reagents. Additionally, a C–H bond oxidation and a C–CN cleavage are proposed to be involved in this cascade process.

Most Men With Erectile Dysfunction Don't Seem to Get Treatment (drugs.com)

Most Men With Erectile Dysfunction Don't Seem to Get Treatment (drugs.com)

Monday 6 May 2013

The antibody-drug conjugate: an enabling modality for natural product-based cancer therapeutics

The antibody-drug conjugate: an enabling modality for natural product-based cancer therapeutics

Nat. Prod. Rep., 2013, 30,625-639
DOI: 10.1039/C3NP20113A, Review Article
Hans-Peter Gerber, Frank E. Koehn, Robert T. Abraham 
In this review, we discuss recent advances related to the construction of ADCs, 
the optimization of ADC safety and efficacy, and the increasingly pivotal roles of 
natural product payloads in the current and future landscape of ADC therapy.
 
 
 The Antibody Drug Conjugate (ADC) is a therapeutic modality consisting of a monoclonal antibody 
attached to a cytotoxic, small-molecule payload. The antibody portion of the ADC serves as a 
transport vehicle that recognizes and binds to a protein antigen expressed in tumor tissues. 
The localized delivery and release of the payload within or near malignant cells allows for targeted 
delivery of a potent cytotoxic agent to diseased tissue, while reducing damage to antigen-negative, 
normal tissues. Recent years have witnessed an explosive increase in ADC-based therapies, 
due mainly to clinical reports of activity in both hematologic and epithelial cancers. 
Accompanying this upsurge in ADC development is a renewed interest in natural product cytotoxins, 
which are typically highly potent cell-killing agents, but suffer from poor drug-like properties and
 narrow safety margins when systemically administered as conventional chemotherapeutics. 
In this review, we discuss recent advances related to the construction of ADCs, 
the optimization of ADC safety and efficacy, and the increasingly pivotal roles of
 natural product payloads in the current and future landscape of ADC therapy.
 

Muscarine, imidazole, oxazole and thiazole alkaloids

Muscarine, imidazole, oxazole and thiazole alkaloids

 

 

 

Nat. Prod. Rep., 2013, Advance Article
DOI: 10.1039/C3NP70006B, Review Article
Zhong Jin
This review summarizes the latest progress on the isolation, identification,
biological activities, and chemical synthesis of these NPs with a literature
 coverage from July 2010 to June 2012.
 link
 Structurally diverse alkaloids containing five-membered heterocyclic subunits, 
such as imidazole, oxazole, thiazole, as well as their saturated congeners, 
are widely distributed in terrestrial and marine organisms and microorganisms. 
These naturally occurring secondary metabolites often exhibit extensive and 
pharmacologically important biological activities. 
The latest progress involving isolation, biological activities, chemical synthetic studies, 
and biosynthetic pathways of these natural products has been summarized in this review.

NEW DRUG APPROVALS a blog by Dr Anthony crasto

NEW DRUG APPROVALS  , my live blog on drugs and all u want to know

link is
http://newdrugapprovals.wordpress.com/

...
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DR ANTHONY MELVIN CRASTO Ph.D , Born in Mumbai in 1964 and graduated from Mumbai University, Completed his  PhD from ICT ,1991,  Mumbai, India in Organic chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues,
Currently he is working with GLENMARK- GENERICS LTD, Research centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India.
Prior to joining Glenmark, he worked with major multinationals like Hoechst Marion Roussel, now Sanofi Aventis,  & Searle India ltd, now Rpg lifesciences, etc. He has worked in Basic research, Neutraceuticals, Natural products, Flavors, Fragrances, Pheromones, Vet Drugs, Drugs, formulation, GMP etc. He has total 25 yrs exp in this field, he is now helping millions, has million hits on google on all organic chemistry websites.
He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 25 year tenure, good knowledge of IPM, GMP, Regulatory aspects, he has  several international drug patents published worldwide .
He suffered a paralytic stroke in dec 2007 and is bound to a wheelchair, this seems to have injected feul in him to help chemists around the world, he is more active than before and is pushing boundaries, he has one lakh connections on all networking sites, He makes himself available to all, contact him on  +91 9323115463, amcrasto@gmail.com
call +91  9323115463  india
ANTHONY MELVIN CRASTO
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MOBILE-+91 9323115463
GLENMARK SCIENTIST , NAVIMUMBAI, INDIA
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