Sunday 27 September 2015

Enhanced production of fructose ester by biocatalyzed continuous flow process


Fatty acid sugar esters are non-toxic, odorless, non-irritanting surfactants. They can be synthesized by renewable resources and are completely biodegradable in aerobic and anaerobic conditions. Their application has been expanded in innumerous areas including pharmaceuticals, cosmetics, detergents and food industry. Lipase-catalyzed esterification have been investigated as a potential substitute to the traditional chemical, demanding milder reaction conditions, allowing better reaction control and providing higher-quality products. So, the lipase catalyzed sugar ester synthesis becomes an interesting strategy for producing biodegradable, non- ionic surfactants. The main disadvantage of this protocol is the poor solubility of substrates and long reaction time required for performed the esterification reaction with moderated to good yields.

Synthesis of 2,3:4,5-O-diisopropylidene-D-frutopyranose (FK) (2)

In a 2000 mL reactor was added 30 g (44.8 mmol) of sucrose and 400 mL of acetone being vigorously mechanically stirred at 5°C for 15 min. Then, 16 mL of concentrate sulfuric acid (H2SO4) was slowly added to the reaction mixture. The solution was kept under stirring for 150 min. Subsequently, the reaction mixture was cooled (0–10°C) in ice bath and neutralized with 50% NaOH (w/v). The pH was adjusted with saturated sodium carbonate. The final mixture was filtered to remove the solids and subsequently, the solvent was evaporated under reduced pressure. The solid crude ketal was diluted with 400 mL of dichloromethane. A 0.5 M H2SO4 solution was added and stirred vigorously for 120 min. The organic phase was separated and washed consecutively with sodium bicarbonate (NaHCO3) and water and dried with anhydrous sodium sulfate (Na2SO4). The solvent was evaporated under reduced pressure until obtaining a white solid, which was crystallized in hexane with 30% final yield after filtration through activated charcoal [19].

Continuous flow reaction procedure

An equimolar stock solution (tert-butylmethyl ether (MTBE), toluene or p-cymene) of 2,3:4,5-O-D-diisopropylidene frutopyranose (FK) and the RePO was prepared (the molarity of the residue was expressed in palmitic acid). The starting mixture was stirred for 5 min while the instrument Asia Flow Reactor was equipped with Omnifit column (2.4 mL) containing the immobilized lipase from R. miehei(600 mg). The reaction parameters were selected on the flow reactor, and processing was started, whereby only pure solvent was pumped through the system until the instrument had achieved the desired reaction parameters and stable processing was assured. At this point, the inlet pipe of the flask was switched to HPLC bottle containing the prepared reaction mixture. After processing through the flow reactor, the inlet tube was dipped back into the flask containing respective pure solvent and processed in order to wash the system of any remaining reactant.

Enhanced production of fructose ester by biocatalyzed continuous flow process

Felipe K Sutili1, Halliny S Ruela1, Daniel De O Nogueira12, Ivana CR Leal2, Leandro SM Miranda1 and Rodrigo OMA De Souza1*

1Biocatalysis and Organic Synthesis Group, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro CEP 22941 909, Brazil
2Faculdade de Farmácia, Federal University of Rio de Janeiro, Rio de Janeiro CEP22941909, Brazil
http://www.sustainablechemicalprocesses.com/content/3/1/6
Sustainable Chemical Processes 2015, 3:6  doi:10.1186/s40508-015-0031-8
The electronic version of this article is the complete one and can be found online at:http://www.sustainablechemicalprocesses.com/content/3/1/6

Rodrigo O. M. A. de Souza

PhD Organic Chemistry
Professor Adjunto III
https://www.researchgate.net/profile/Rodrigo_De_Souza4
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Wednesday 23 September 2015

Firming COFs up takes Michael reaction catalysis forward


cof
Jiang's team took this covalent organic framework and modified it to make it more stable © NPG


Firming COFs up takes Michael reaction catalysis forward

News item thumbnail
Chemists stabilise hexagonal layers that form nanochannels, which help speed up conversions

see


By making formerly fragile covalent organic frameworks (COFs) resistant to harsh conditions, researchers in Japan have created what they think could be a powerful new catalyst concept. Donglin Jiang’s team at the National Institutes of Natural Sciences in Okazaki have already used their chiral COFs to enable selective and high-yielding Michael reactions with low-reactivity ketones. They believe theirs is the first example of a heterogeneous catalyst based on a crystalline porous material used in this reaction.

IMS

Dongling
 jiang
Tel: +81-564-59-5520
Fax: +81-564-59-5520
Institute for Molecular Science, National Institutes of Natural Science
Sokendai (Graduate University for Advanced Studies)
5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan












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Tuesday 22 September 2015

Recent Developments in Chemistry of Phthalazines



From hydrazine and hydrazine derivatives
 
Hydrazine and hydrazine derivatives are the most common reagents used for the synthesis of phthalazinone derivatives via their reactions with phthalic anhydride, phthalides, phthalimides etc.
 
Hydrazines with anhydrides: Several methods were reported for the preparation of phthalazinones derivatives. These methods mainly involve the reaction of phthalic anhydrides with hydrazine hydrate in the presence of acetic acid [42-44].
 
Phthalazinones 5,7-9 were synthesized from commercially available phthalic anhydride in 2-3 steps as depicted in (Scheme 1 and 2) [45-51].
 
Additionally, reaction of phthalic anhydride and aromatic hydrocarbons in the presence of anhydrous aluminum chloride under Friedel-Craft’s conditions afforded 2-aroylbenzoic acids 10 which treated with hydrazine hydrate and hydrazine derivatives to give the phthalazine (2H)-1-one 11,12 [52-57] (Scheme 3).
Recent Developments in Chemistry of Phthalazines
Fatma SM Abu El-Azm*, Mahmoud R Mahmoud, and Mohamed H Hekal
Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt
Corresponding Author :Fatma SM Abu El-Azm
Chemistry Department
Faculty of Science
Ain Shams University, Abbassia
Cairo, Egypt, Post code 11566
Tel: 0201220383276
E-mail: ftmsaber@yahoo.com
http://www.omicsonline.org/open-access/recent-developments-in-chemistry-of-phthalazines-2161-0401.1000132.php?aid=40611
 
Citation: El-Azm FSMA, Mahmoud MR, Hekal MH (2015) Recent Developments in Chemistry of Phthalazines. Organic Chem Curr Res 4:132. doi: 10.4172/2161-0401.1000132
Chemistry Department
Faculty of Science
Ain Shams University, Abbassia
Cairo, Egypt








/////Phthalazine derivatives,  Pyrazolophthalazines,  Indazolophthalazines,  [1,2,4] Triazolophthalazines, Fatma SM Abu El-Azm

Saturday 19 September 2015

GREEN ACETANILIDE SYNTHESIS AND SPECTRAL ANALYSIS










 



 

















 



 



H-1 NMR Spectrum of Acetanilide

The following chemical shifts were reported [1,2] for the protons of acetanilide:
CH3 [1] 2.1
para-H [1] 7.0
meta-H [1] 7.2
ortho-H [1] 7.4
NH [2] ca. 8.75
[1] M. Hesse, H. Meier, B. Zeeh: Spektroskopische Methoden in der organischen Chemie, Georg Thieme Verlag, Stuttgart, 2nd ed., 1984, p. 263.
[2] from a H-1 NMR spectrum shown by Stephen Jones


C-13 NMR Spectrum of Acetanilide

The following chemical shifts were reported [1] for the carbons of acetanilide:
CH3 [1] 24.1
para-C [1] 124.1
meta-C [1] 128.7
ortho-C [1] 120.4
ipso-C [1] 138.2
CO [1] 169.5
[1] M. Hesse, H. Meier, B. Zeeh: Spektroskopische Methoden in der organischen Chemie, Georg Thieme Verlag, Stuttgart, 2nd ed., 1984, p. 263.
[2] there is a C-13 NMR spectrum shown by Stephen Jones



Acetanilide
Acetanilide
Names
IUPAC names
N-phenylacetamide
N-phenylethanamide
Identifiers
103-84-4 Yes
ChEBI CHEBI:28884 Yes
ChEMBL ChEMBL269644 Yes
ChemSpider 880 Yes
EC number 203-150-7
Jmol-3D images Image
KEGG C07565 Yes
UNII SP86R356CC Yes
Properties[1][2]
C8H9NO
Molar mass 135.17 g·mol−1
Odor Odorless
Density 1.219 g/cm3
Melting point 114.3 °C (237.7 °F; 387.4 K)
Boiling point 304 °C (579 °F; 577 K)
<0.56 g/100 mL (25 °C)
Solubility Soluble in ethanol, diethyl ether, acetone, benzene
log P 1.16 (23 °C)
Vapor pressure 2 Pa (20 °C)
Hazards[3][4]
Safety data sheet External MSDS
GHS pictograms Acute Tox. (oral) 4
GHS signal word WARNING
H302
P264, P270, P301+312, P330, P501
Flash point 174 °C (345 °F; 447 K)
545 °C (1,013 °F; 818 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 Yes verify (what isYes/?)
Infobox references




Drying acetanilide



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