Sweet success for bio-battery

Green Chemistry International


An enzyme cascade strips electrons from glucose and turns it into electricity that could be used to power a mobile phone © NPG

Sugar is an excellent source of energy. Most living cells generate their energy from glucose by passing it down an enzymatic chain that converts it into different sugars. This enzymatic cascade provides the necessary energy to create an electrochemical gradient. This, in turn, can be used to power an enzyme that synthesises adenosine triphosphate (ATP) – the universal biological energy currency. However, extracting this energy from a sugar if you’re not a biological organism is tricky – short of combustion, which is impractical to power handheld electronics.

To fuel their battery the team used maltodextrin – a polymer made up of glucose subunits. They then created an entirely new synthetic enzymatic pathway to extract energy from the sugar. Using 13 different enzymes they were able to strip…

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Chemical Process Development

Lamentations on Chemistry

Lots of semi-batch process development and safety work going on in my lab. We use our reaction calorimeter for a variety of studies now. Naturally we want to know about energy accumulation with a given feed rate or any unforeseen induction or initiation problems in a reaction. We can also home in on recommendations for safe feed rates of reactants into a reaction mass.

What I am beginning to learn from the RC1 work is that running a reaction at low temperature is frequently done for sketchy reasons. Unless there are selectivity or side product issues, you really have to question why the reaction is specified to be run at low temperature. I think some of it comes from habit gained in grad school.  Low temperature may introduce dangerous situations with abrupt initiation by accumulation of unreacted reagents. Or it may lead to overly long feed time with the associated costs of added…

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Sweet crystallography – the crystal structure of sucrose


What does it look like?

What is it?

What’s within that sugar cube floating in your coffee?  There a number of forms of sugars, but the one that sits as a white powder in our cupboards is sucrose.   The sucrose molecule itself is a combination of a glucose and fructose molecule (you can see that each of the molecule have two parts to them).   This means it has a very specific way of packing together to form a solid.   Each sucrose molecule is made of carbon (brown), oxygen (red) and hydrogen (pink).

Where did the structure come from?

Given how important sucrose is to our diets, and how much money is made from sugar, finding its crystal structure was very important question of early crystallography.  One of the challenges to finding its structure was the fact that it is composed entirely of ‘light elements’ only carbon, oxygen and hydrogen.  The…

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New Short Strategy for the Synthesis of the Dibenz[b,f]oxepin Scaffold

abstract graphic

David R. R. Moreno 1, Giorgio Giorgi 2, Cristian O. Salas 1 and Ricardo A. Tapia 1,*
1 Departamento de Química Orgánica, Facultad de Química, Pontificia Universidad Católica de
Chile, Santiago 7820436, Chile; E-Mails: drmoreno@uc.cl (D.R.R.M.); cosalas@uc.cl (C.O.S.)

chile flag
2 Departamento de Química Orgánica y Farmacéutica, Facultad de Farmacia,
Universidad Complutense, Madrid 28040, Spain;E-Mail: giorgiogiorgi@farm.ucm.es

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* Author to whom correspondence should be addressed; E-Mail: rtapia@uc.cl;
Tel.: +56-2-2354-4429; Fax: +56-2-2354-4744.

Molecules 201318(12), 14797-14806; doi:10.3390/molecules181214797

Download PDF Full-text (257 KB) |  Supplementary Files

(This article belongs to the Section Organic Synthesis)
 In this report a short and efficient synthesis of the dibenz[b,f]oxepin framework through intramolecular SNAr and McMurry reactions is described. The diaryl ethers required for the McMurry reaction have been obtained in good yields under microwave-assisted conditions of the reaction of salicylaldehydes with fluorobenzaldehydes without catalysts. Application of an intramolecular McMurry reaction to the synthesized diarylethers using TiCl4/Zn in THF gave the target dibenzo[b,f]oxepin system in 53%–55% yields.
Molecules 2013, 18, 14797-14806; doi:10.3390/molecules181214797

In conclusion, we have developed a short synthesis of dibenzo[b,f]oxepin derivatives using SNAr
and intramolecular McMurry reactions. An efficient process to obtain diarylethers through SNAr
reaction of salicylaldehydes with fluorobenzaldehydes using microwave irradiation is described.
McMurry reaction of diarylethers using TiCl4 and Zn in THF afforded the target tricyclic system in
reasonable yields (53%–55%). Further work on the synthesis of natural and pharmacologically active
dibenzo[b,f]oxepins are under way.

abstract graphic



Download PDF Full-text (257 KB) | Download


Supplementary Files   DOWNLOAD


compd 5a


Dibenz[b,f]oxepin (5a).

Stilbene 3 (215 mg, 0.5 mmol) was added to a solution of KOH (900 mg,
16 mmol) in a mixture of EtOH (15 mL) and H2O (15 mL) and the suspension was heated under reflux
for 1 h. After cooling, the reaction mixture was acidified with aqueous HCl (10%) to pH 4 and
extracted with CH2Cl2 (3 × 25 mL). The combined organic extracts were washed with saturated
aqueous NaHCO3, dried, and filtered through a short column of silica gel. After the removal of the
solvent, the residue was dissolved in DMSO (5.0 mL) and Cs2CO3 (651.6 mg, 2.0 mmol) was added.
The reaction mixture was heated in a microwave reactor at 180 °C for 15 min. After cooling, the
solvent was evaporated under reduced pressure and the crude product was purified by flash column
chromatography (silica gel, EtOAc-hexanes; 1:9) to afford 5a (70 mg, 72%),

mp 108.5–109.5 °C
(Lit. 106–108 °C [34], 110–111 °C [35]).

IR (KBr): 􀟥􀷤 max 3069, 3044, 1483, 798 cm−1.
1H-NMR (acetone-d6) δ 6.82 (s, 2H, Two protons of -CH=CH- ), 7,19 (t, J = 7,8 Hz, 2H), 7.25 (d, J = 7.8 Hz, 2H), 7.30 (d, J = 7.8 Hz,2H), 7.38 (t, J = 7.8 Hz, 2H).

13C-NMR (acetone-d6) δ 122.9, 126.6, 131.1, 131.6, 131.7, 132.3, 159.1.

The Mapuche people were the original inhabitants of southern and central Chile.

Fighting during the War of the Pacific: The Battle of Iquique on 21 May 1879.

Parinacota volcano in northern Chile

Araucanian Indians and Huasos in Chile, 19th century

The Catholic Monarchs in the Capitulation of Granada, the end of the Reconquista and the unification of the kingdoms forming actual Spain.




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Oxindole as starting material in organic synthesis

Oxindole as starting material in organic synthesis (13-8074LR)

Arkivoc 2013 Part (i): Special Issue ‘Reviews and Accounts’ [pp. 470-535]

Full Text: PDF (1,621K)

http://www.arkat-usa.org/get-file/48468/    ,,,,,,,,,,,,,,,,,,,,,,free access

Ghodsi Mohammadi Ziarani,a* Parisa Gholamzadeh,aNegar Lashgari,a,b and Parvin Hajiabbasia

a  Department_of_ChemistryAlzahra University, Vanak Square, P.O. Box 1993891176,
Tehran, Iran
b  School of Chemistry, College of Science, University of Tehran, P.O. Box 14155-6455,
Tehran, Iran

This review highlights the advances in the use of oxindole as starting material in the synthesis of
various organic compounds and drugs. The reactions can be performed on different reactive sites of
oxindole which are the carbonyl group, C-3 site, nitrogen atom, and aromatic ring. In addition, the
roles of oxindole in one-pot and domino reactions are discussed.

Persian miniature depicting Timur‘s campaign in India

File:4758976353 tehran b.jpg
teheran at night
Ayatollah Khomeini returns to Iran after 14 years exile on February 1, 1979.
Reza Smizadeh