Studies on Nitration of Phenol over Solid Acid Catalyst by Lipika Das, Koushi...crimsonpublisherspps
Phenol was selectively nitrated in liquid phase to produce ortho-nitrophenol using dilute nitric acid (30%) at room temperature in presence of hydrochloric acid treated γ-alumina. Initially Al (NO3) and NH4HCO3 were reacted to prepare Al (OH)3 which on successive calcinations at 550 0C for 5h produce γ-alumina. The γ-alumina was characterized by BET, XRD, SEM and NH3-TPD analysis. The XRD profile confirmed the crystalline structure of the solid acid catalyst γ-alumina. The NH3-TPD analysis showed the development of lewis acidity on the surface of hydrochloric acid treated γ-alumina. The effects of various parameters such as concentration of reactants, types of catalyst, weight of the catalyst, solvent, temperature and time of reaction have been studied. The kinetics of the reaction was also investigated
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Synthesis And Characterization of Novel Processable Poly (EtherAzomethine)S C...inventionjournals
The novel dialdehyde 1,1-bis[4-(4-benzaldehyde oxy) phenyl] cyclopentane (III) (BBPC) was synthesized starting from cyclopentanone and phenol to give 1, 1-Bis (4-hydroxy phenyl) cyclopentane (II); followed by reaction with p- fluorobenzaldehyde in N, N-dimethyl formamide (DMAc), containing anhydrous potassium carbonate. New series of poly (ether – azomethine)s were synthesized from (BBPC) with different diamines such as 4, 4’- diamino diphenyl ether (ODA),4,4’-diaminodiphenyl methane(MDA),4-aminophenyl sulfone(SDA), p-phenylene diamines, etc. in DMAc with 5 wt% LiCl by solution polycondensation technique. Inherent viscosities of these polymers were in the range 0.19 to 0.42 dL/g indicating formation of moderate molecular weights. These polymers exhibited good solubility in various polar aprotic solvents such as Nmethylpyrrolidone (NMP), N, N-dimethylacetamide (DMAc) and N,N-dimethyl formamide (DMF), etc. X-Ray diffraction pattern of polymers showed that introduction of cardo cyclopentylidene moiety containing ether linkage would disrupt the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA showed excellent thermal stability of polymers. The structure- property correlation among these polyazomethines were studied; in view of their potential applications as high performance polymers.
Studies on Nitration of Phenol over Solid Acid Catalyst by Lipika Das, Koushi...crimsonpublisherspps
Phenol was selectively nitrated in liquid phase to produce ortho-nitrophenol using dilute nitric acid (30%) at room temperature in presence of hydrochloric acid treated γ-alumina. Initially Al (NO3) and NH4HCO3 were reacted to prepare Al (OH)3 which on successive calcinations at 550 0C for 5h produce γ-alumina. The γ-alumina was characterized by BET, XRD, SEM and NH3-TPD analysis. The XRD profile confirmed the crystalline structure of the solid acid catalyst γ-alumina. The NH3-TPD analysis showed the development of lewis acidity on the surface of hydrochloric acid treated γ-alumina. The effects of various parameters such as concentration of reactants, types of catalyst, weight of the catalyst, solvent, temperature and time of reaction have been studied. The kinetics of the reaction was also investigated
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Synthesis And Characterization of Novel Processable Poly (EtherAzomethine)S C...inventionjournals
The novel dialdehyde 1,1-bis[4-(4-benzaldehyde oxy) phenyl] cyclopentane (III) (BBPC) was synthesized starting from cyclopentanone and phenol to give 1, 1-Bis (4-hydroxy phenyl) cyclopentane (II); followed by reaction with p- fluorobenzaldehyde in N, N-dimethyl formamide (DMAc), containing anhydrous potassium carbonate. New series of poly (ether – azomethine)s were synthesized from (BBPC) with different diamines such as 4, 4’- diamino diphenyl ether (ODA),4,4’-diaminodiphenyl methane(MDA),4-aminophenyl sulfone(SDA), p-phenylene diamines, etc. in DMAc with 5 wt% LiCl by solution polycondensation technique. Inherent viscosities of these polymers were in the range 0.19 to 0.42 dL/g indicating formation of moderate molecular weights. These polymers exhibited good solubility in various polar aprotic solvents such as Nmethylpyrrolidone (NMP), N, N-dimethylacetamide (DMAc) and N,N-dimethyl formamide (DMF), etc. X-Ray diffraction pattern of polymers showed that introduction of cardo cyclopentylidene moiety containing ether linkage would disrupt the chain regularity and packing, leading to amorphous nature. Thermal analysis by TGA showed excellent thermal stability of polymers. The structure- property correlation among these polyazomethines were studied; in view of their potential applications as high performance polymers.
Studies on Nitration of Phenol over Solid Acid Catalyst | Crimson PublishersDanesBlake
Phenol was selectively nitrated in liquid phase to produce ortho-nitrophenol using dilute nitric acid (30%) at room temperature in presence of hydrochloric acid treated γ-alumina. Initially Al(NO3) and NH4HCO3 were reacted to prepare Al (OH)3 which on successive calcinations at 550 ᴼC for 5h produce γ-alumina. The γ-alumina was characterized by BET, XRD, SEM and NH3-TPD analysis. The XRD profile confirmed the crystalline structure of the solid acid catalyst γ-alumina. The NH3-TPD analysis showed the development of lewis acidity on the surface of hydrochloric acid treated γ-alumina. The effects of various parameters such as concentration of reactants, types of catalyst, weight of the catalyst, solvent, temperature and time of reaction have been studied. The kinetics of the reaction was also investigated.
Liquid crystal bio-based epoxy coating with enhanced performanceIJERA Editor
Tetrafunctional rosin based epoxy was synthesized and cured with either rosin based hardener or conventional
phenylene diamine to study the feasibility of producing high performance thermosetting polymer from
renewable resource. The chemical structure of the prepared epoxy was confirmed by elemental analysis, FTIR,
1HNMR, UV, total acid number and epoxy equivalent weight. Dynamic mechanical (DMA) and
thermogravimetric (TGA) analyses results indicate that fully biobased epoxy system possesses high glass
transition temperature (Tg), high modulus (G`) and improved thermal stability.
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
TOTAL POLYPHENOLS AND DPPH FREE RADICALS SCAVENGING ACTIVITY IN SIX LEAFY VEG...Md. Kamaruzzaman
TOTAL POLYPHENOLS AND DPPH FREE RADICALS SCAVENGING ACTIVITY IN SIX LEAFY VEGETABLES OF BANGLADESH
Harun-Ar-Rashid, Sheikh Julfikar Hossain, Sk. Amir Hossain, Md Mahfuzur Rahman, Md. Kamaruzzaman
Synthesis of Oxygenated Fuel Additives via Acetylation of Bio-Glycerol over H...crimsonpublisherspps
Growing global biodiesel production demands valorization of bio-glycerol derived from biodiesel, which is crucial to make bio refinery process economical. Hence, a series of H2SO4 modified sulfonated Montmorillonite K10 catalysts were synthesized, characterized and evaluated for acetylation of bio- glycerol with acetic acid to produce mono acetin (MAG), di acetin (DAG), tri acetin (TAG) and di-glycerol tri-acetate (DGTA), which are the oxygenated fuel additives and facilitate the economic viability of biodiesel production so the bio refinery. The synthesized catalysts were characterized by compressive suite of characterization techniques such as powder X-ray diffraction (XRD), low temperature N2physisorption, temperature programmed ammonia desorption (TPAD) and Fourier transform infrared (FTIR)
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Synthesis of Oxygenated Fuel Additives via Acetylation of Bio-Glycerol over H...DanesBlake
Abstract
Growing global biodiesel production demands valorization of bio-glycerol derived from biodiesel, which is crucial to make biorefinery process economical. Hence, a series of H2SO4 modified sulfonated Montmorillonite K10 catalysts were synthesized, characterized, and evaluated for acetylation of bio- glycerol with acetic acid to produce mono acetin (MAG), di acetin (DAG), tri acetin (TAG), and di-glycerol tri-acetate (DGTA), which are the oxygenated fuel additives and facilitate the economic viability of biodiesel production so the biorefinery. The synthesized catalysts were characterized by a compressive suite of characterization techniques such as powder X-ray diffraction (XRD), low temperature N2 physisorption, temperature-programmed ammonia desorption (TPAD), and Fourier transform infrared (FTIR). The glycerol conversion and product distribution results were found to correlate with the acidity and textural properties of the catalyst. 20% (w/w) SO4/K10 was revealed to be a promising catalyst for glycerol acetylation with 99% glycerol conversion and with respective yield towards MAG, DAG, TGA and DGTA of 23%, 59%, 15%, and 2%. Moreover, 20% (w/w) SO4/K10 catalyst
was found to maintain the stable catalytic activity for three reaction cycles. However, the partial catalyst deactivation was observed after third reaction cycle, partly due to deposition of coke and loss of active sites during the reaction. https://crimsonpublishers.com/pps/fulltext/PPS.000501.php
A novel flame retardant application technique was developed for cotton apparel fabric using spirocyclic
pentaerythritol di (phosphoryl chloride) (SPDPC), which was further synthesized into bis diglycol spirocyclic
pentaerythritol bisphosphorate (BSPB). The flame retardant agent was then attached to the fabric using a
sol-gel process. The treated fabric was tested on a vertical flame tester which showed very high flame
retardancy as compared to the untreated cotton. TGA analysis exhibited a slow rate of weight loss and
higher ultimate degradation temperature for the FR treated sample. The FR treated sample showed modest
loss in strength while retaining 86.4% of its original strength. The fabric’s appearance did not alter and the
change in stiffness was insignificant as a result of the FR finish.
Studies on Nitration of Phenol over Solid Acid Catalyst | Crimson PublishersDanesBlake
Phenol was selectively nitrated in liquid phase to produce ortho-nitrophenol using dilute nitric acid (30%) at room temperature in presence of hydrochloric acid treated γ-alumina. Initially Al(NO3) and NH4HCO3 were reacted to prepare Al (OH)3 which on successive calcinations at 550 ᴼC for 5h produce γ-alumina. The γ-alumina was characterized by BET, XRD, SEM and NH3-TPD analysis. The XRD profile confirmed the crystalline structure of the solid acid catalyst γ-alumina. The NH3-TPD analysis showed the development of lewis acidity on the surface of hydrochloric acid treated γ-alumina. The effects of various parameters such as concentration of reactants, types of catalyst, weight of the catalyst, solvent, temperature and time of reaction have been studied. The kinetics of the reaction was also investigated.
Liquid crystal bio-based epoxy coating with enhanced performanceIJERA Editor
Tetrafunctional rosin based epoxy was synthesized and cured with either rosin based hardener or conventional
phenylene diamine to study the feasibility of producing high performance thermosetting polymer from
renewable resource. The chemical structure of the prepared epoxy was confirmed by elemental analysis, FTIR,
1HNMR, UV, total acid number and epoxy equivalent weight. Dynamic mechanical (DMA) and
thermogravimetric (TGA) analyses results indicate that fully biobased epoxy system possesses high glass
transition temperature (Tg), high modulus (G`) and improved thermal stability.
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
TOTAL POLYPHENOLS AND DPPH FREE RADICALS SCAVENGING ACTIVITY IN SIX LEAFY VEG...Md. Kamaruzzaman
TOTAL POLYPHENOLS AND DPPH FREE RADICALS SCAVENGING ACTIVITY IN SIX LEAFY VEGETABLES OF BANGLADESH
Harun-Ar-Rashid, Sheikh Julfikar Hossain, Sk. Amir Hossain, Md Mahfuzur Rahman, Md. Kamaruzzaman
Synthesis of Oxygenated Fuel Additives via Acetylation of Bio-Glycerol over H...crimsonpublisherspps
Growing global biodiesel production demands valorization of bio-glycerol derived from biodiesel, which is crucial to make bio refinery process economical. Hence, a series of H2SO4 modified sulfonated Montmorillonite K10 catalysts were synthesized, characterized and evaluated for acetylation of bio- glycerol with acetic acid to produce mono acetin (MAG), di acetin (DAG), tri acetin (TAG) and di-glycerol tri-acetate (DGTA), which are the oxygenated fuel additives and facilitate the economic viability of biodiesel production so the bio refinery. The synthesized catalysts were characterized by compressive suite of characterization techniques such as powder X-ray diffraction (XRD), low temperature N2physisorption, temperature programmed ammonia desorption (TPAD) and Fourier transform infrared (FTIR)
https://crimsonpublishers.com/pps/fulltext/PPS.000501.php
For more open access journals in Crimson Publishers
Please click on link: https://crimsonpublishers.com
For More Articles on Prime research material
Please click on: https://crimsonpublishers.com/pps/
Synthesis of Oxygenated Fuel Additives via Acetylation of Bio-Glycerol over H...DanesBlake
Abstract
Growing global biodiesel production demands valorization of bio-glycerol derived from biodiesel, which is crucial to make biorefinery process economical. Hence, a series of H2SO4 modified sulfonated Montmorillonite K10 catalysts were synthesized, characterized, and evaluated for acetylation of bio- glycerol with acetic acid to produce mono acetin (MAG), di acetin (DAG), tri acetin (TAG), and di-glycerol tri-acetate (DGTA), which are the oxygenated fuel additives and facilitate the economic viability of biodiesel production so the biorefinery. The synthesized catalysts were characterized by a compressive suite of characterization techniques such as powder X-ray diffraction (XRD), low temperature N2 physisorption, temperature-programmed ammonia desorption (TPAD), and Fourier transform infrared (FTIR). The glycerol conversion and product distribution results were found to correlate with the acidity and textural properties of the catalyst. 20% (w/w) SO4/K10 was revealed to be a promising catalyst for glycerol acetylation with 99% glycerol conversion and with respective yield towards MAG, DAG, TGA and DGTA of 23%, 59%, 15%, and 2%. Moreover, 20% (w/w) SO4/K10 catalyst
was found to maintain the stable catalytic activity for three reaction cycles. However, the partial catalyst deactivation was observed after third reaction cycle, partly due to deposition of coke and loss of active sites during the reaction. https://crimsonpublishers.com/pps/fulltext/PPS.000501.php
A novel flame retardant application technique was developed for cotton apparel fabric using spirocyclic
pentaerythritol di (phosphoryl chloride) (SPDPC), which was further synthesized into bis diglycol spirocyclic
pentaerythritol bisphosphorate (BSPB). The flame retardant agent was then attached to the fabric using a
sol-gel process. The treated fabric was tested on a vertical flame tester which showed very high flame
retardancy as compared to the untreated cotton. TGA analysis exhibited a slow rate of weight loss and
higher ultimate degradation temperature for the FR treated sample. The FR treated sample showed modest
loss in strength while retaining 86.4% of its original strength. The fabric’s appearance did not alter and the
change in stiffness was insignificant as a result of the FR finish.
UV Mutagenesis Enhanced Biotransformation Efficiency of Rutin to Isoquercitri...iosrjce
In order to obtain high biotransformation efficiency of rutin to isoquercitrin (quercetin-3-Oglucoside),
Bacillus litoralis C44 was treated by UV mutagenesis to screen the thermo- and alkali-tolerant
mutants, for these conditions allow for a very high substrate concentration. The optimal mutagen dose for strain
C44 was irradiation for 50s with a 15W UV lamp from 30 cm away. The mutants were preliminary screened by
quantitative TLC, and 16 mutant strains were faced to second-screening by HPLC. As a result, a genetic stable
mutant strain UV-2-45 was obtained, which got a biotransformation rate of 3.9 times more than the original
strain Bacillus litoralis C44, and its mole yield reached as high as 91% from 3 g/L of rutin in glycine-sodium
hydroxide buffer (pH 9.0) at 45°C for 2 days.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Trisodium phosphate, TSP was utilized to valorize abundant glycerol to fine chemicals (Glycerol carbonate). The catalyst displayed superior stability and activity over nine times reuse. Hence, its strongly recommended for potential industrial application.
Determination of Immobilization Process Parameters of Corynebacterium glutami...IJERA Editor
The parameters of the immobilized process of Corynebacterium glutamicum on kappa carrageenan were identified by
Plackett-Burman matrix, and the experiments were designed by response surface methodology having the central
composite designs (RSM-CCD). The maximum yield of cell immobilization on kappa carrageenan carrier reached at
78% ± 2%. Optimal parameters were 3 grams kappa carrageenan per 100 militters sterile water and 58.58 million
cfu/mL, forming gels at 100C for 25 minutes and the speed when soaking particles of 150 rpm for 120 minutes in 0.58
M potassium chlorua solvent. The immobile finished products are applied in L-lysine production, their reusing ability
is 3 times and the total yield of L-lysine was accumulated 93 g/L in medium during 96 fermented hours. The L-lysine
productivity of the batch fermentation was 0.969 g.L-1
.h-1
. And the set-up storage conditions are the mixed solvent of
CaCl2 0.5% (w/v) and KCl 0.5% (w/v); pH is 7.0 in 40C. After 60 storage days, the survival cell rate was remained
51%.
Chemical and Physical properties of Cassava Starch-Cm-Chitosan-Acrylic Acid Hydrogel prepared from radiation –induced crosslinking
Gatot Trimulyadi Rekso
Center for Application of Isotopes and Radiation- National Nuclear Energy Agency
Jl. Lebak Bulus Raya No. 49, Jakarta-Selatan, Indonesia
Corresponding author; e-mail; gatot2811@yahoo.com ,
Fax: +62-21-.7513270, HP ; 08129419442
Abstract— Biofuel production from microalgae biomass appears as a promising long term alternative. Dunaliella tertiolecta is a microalgae with high tolerance to salinity, temperature, and light, making it relatively easy to grow. The aim of this study was to establish a pilot-scale culture to evaluate the biomass yield and bioethanol production. The cell culture of D. tertiolecta was started in 20 ml tubes and escalated to 20 L containers. The biomass yield was 0.153 g L-1 of dry basis (db) and its characterization showed protein (37% db) as major component followed by carbohydrates (35.6), lipids (13% db) and ash (6.5%). The carbohydrate fraction was composed of starch (27.1% db) and fiber (8.5 %) and its neutral sugar characterization yield glucose (91% molar). The main components of the lipid fraction were linolenic and palmitic acids. The biomass was subjected to an acid pre-treatment for the saccharification of complex carbohydrates, and the hydrolyzed biomass was fermented by Saccharomyces cerevisiae. It was possible to produce 0.615 ml g-1 of ethanol. In conclusion, D. tertiolecta has the potential for bioethanol production, making it a promising option for the biofuels future.
In this work a new prodrug polymer was
prepared with two attachment groups (amid-ester), using di
functional spacer such as ethanol amine, which could react with
polyacrylic acid producing amide group, with remain ethanol
terminal group which could react with captopril acyl chloride,
producing ester group with extended the arm substituted drug to
improve the hydrolysis and to prevent the steric effect of polymer
chains. Many advantages enhanced the prodrug of polymer. The
prepared polymers were characterized by FTIR, 1H –NMR
spectroscopies. Controlled drug release was studied in different
pH values at 37℃, using UV. Spectra with comparing with
calibration curve. The modification percentage test was studied,and swelling percentage was calculated and all physical properties were observed.
A comparison of chemical treatment methods for the preparation of rice husk c...Agriculture Journal IJOEAR
Abstract— NaOH, H2O2 and NaOH/H2O2 treatment methods were investigated to eliminate the lignin and hemicellulose distributed in the lignocellulosic matrix of rice husk. In order to prevent the decomposition of H2O2 at higher temperatures, a low temperature treatment for 4 hours has been performed. A composition analysis indicated that NaOH/H2O2 may achieve the highest concentration of α-cellulose, but had the lowest overall solid recovery rate. Both FTIR and TGA results confirmed that only the H2O2 treated rice husk contained hemicellulose residue, which could be found at the absorption peak 1740 cm-1. The TGA analysis demonstrated the NaOH/H2O2 modified rice husks presented the most uniform structure. The SEM gave a clear picture of the raw rice husks and modified rice husks.
1. Biotransformation of benzaldehyde to
L-phenylacetylcarbinol (L-PAC) by Torulaspora
delbrueckii and conversion to ephedrine by
microwave radiation
Vilas B Shukla,1
Virendra R Madyar,2
Bhushan M Khadilkar2
and
Pushpa R Kulkarni1
*
1
Food & Fermentation Technology Division, University Dept of Chemical Technology, University of Mumbai (UDCT), Nathalal Parekh Marg,
Matunga, Mumbai - 400 019, India
2
Organic Chemistry Division, University Dept of Chemical Technology, University of Mumbai (UDCT), Nathalal Parekh Marg, Matunga,
Mumbai - 400 019, India
Abstract: In a 5dm3
stirred tank reactor, bioconversion of 30g benzaldehyde by cells of Torulaspora
delbrueckii yielded 22.9g of pure L-phenylacetylcarbinol (L-PAC). Facile functional group trans-
formation of 4.5g of L-PAC to 2-(methylimino)-1-phenyl-1-propanol by exposure to microwave
irradiation for 9min resulted in 2.48g of product. Conversion of 4.8g of 2-(methylimino)-1-phenyl-1-
propanol to 3.11g of ephedrine was achieved by exposure to microwaves in a reaction time of 10min.
The identity of all the products was con®rmed by 1
H NMR and FT-IR analysis.
# 2002 Society of Chemical Industry
Keywords: benzaldehyde; biotransformation; ephedrine; L-phenylacetylcarbinol; imine formation; microwave
irradiation; reduction; Torulaspora delbrueckii
INTRODUCTION
Ephedrine is an important drug used as a decongestant
and anti-asthmatic. L-Ephedrine is obtained from
dried plants of various species of the genus Ephedra
by initial treatment with alkali, followed by extraction
with organic solvent. Extraction, puri®cation and
isolation of these drugs is time-consuming, costly
and complicated by the presence of undesired by-
products. L-Phenylacetylcarbinol (L-PAC; B) which is
a precursor for ephedrine is produced by biotransfor-
mation of benzaldehyde (A) using yeast cultures. The
chemical conversion of L-PAC to ephedrine has
proved to be more advantageous than the extraction
route. L-PAC could be converted by a chemical
reductive amination with methylamine to optically
pure L-ephedrine. The use of microwave irradiation
for chemical synthesis is of increasing importance,4
since it provides a simple alternative to classical
chemical routes with rapid reactions yielding high
conversion and selectivity. The present work was
undertaken to explore the possibility of conducting the
synthesis using microwaves as an alternative to these
routine chemical synthetic reactions. A two-step
simple synthetic reaction was carried out in a homo-
geneous reaction medium under exposure to micro-
waves. A homogeneous reaction medium ensures
better thermal homogeneity under microwave heating
and facilitates scale-up of the reaction. The procedure
is superior to methods involving complex hydrogena-
tion5
procedures and those involving reduction of
protected cyanohydrins.6
The L-PAC required for
ephedrine synthesis was produced by bioconversion of
benzaldehyde using a yeast isolate identi®ed as Torula-
spora delbrueckii and which is capable of producing
L-PAC from benzaldehyde.7
MATERIALS
Microbial media components were obtained from Hi-
Media Ltd, Mumbai, methylamine and sodium boro-
hydride (AR grade) from SD Fine Chemicals Ltd,
Mumbai and methanol and diethylether from Merck
India Ltd, Mumbai. For GC analysis standard
benzaldehyde and benzyl alcohol (Sigma Chemicals
Co, St Louis, USA) were used while L-PAC and
PAC-diol were obtained by puri®cation of the
biotransformation broth as described previously.8
For biotransformation of benzaldehyde to L-PAC a
yeast isolate from molasses, identi®ed as T delbrueckii,
was used. The maintenance medium9
for the yeast
(Received 19 July 2001; accepted 23 September 2001)
* Correspondence to: Pushpa R Kulkarni, Food & Fermentation Technology Division, University Dept of Chemical Technology, University of
Mumbai (UDCT), Nathalal Parekh Marg, Matunga, Mumbai - 400 019, India
E-mail: rekha@foodbio.udct.ernet.in
# 2002 Society of Chemical Industry. J Chem Technol Biotechnol 0268±2575/2002/$30.00 137
Journal of Chemical Technology and Biotechnology J Chem Technol Biotechnol 77:137±140 (online: 2002)
DOI: 10.1002/jctb.534
2. comprised (gdmÀ3
): glucose 20, peptone 10, yeast
extract 10, and agar 20, at pH 5.5, while the growth
medium comprised (gdmÀ3
): glucose 30, peptone 20,
and yeast extract 10, at pH 5.5. The biotransformation
medium comprised (gdmÀ3
): glucose 30, and peptone
20, at pH 4.5. The maintenance medium, growth
medium and biotransformation medium were used
only for biological reactions. For chemical reactions
using microwave irradiation a modi®ed IFB Neutron
kitchen oven (760W output and 2450MHz fre-
quency) was used.
EXPERIMENTAL
Step 1: Biotransformation of benzaldehyde to
L-phenylacetylcarbinol (L-PAC) using T delbrueckii
cellmass
A: Maintenance and growth of T delbrueckii
To maintain T delbrueckii one loop full of yeast suspen-
sion was streaked on the agar slants of the maintenance
medium. The slants were incubated at 30°C for 24h
and stored at 2±8°C until further transfer or when
used for incubating the cultures.
Onecm3
of 24-h-old suspension of the organism
containing 106
yeast cells was inoculated into 9cm3
of
growth medium and incubated on a rotary shaker at
30(Æ2°C) at 240rpm for 24h. The culture obtained
was inoculated into 100cm3
of growth medium and
incubated for 24h under the same conditions. The
220cm3
of culture pooled from two ¯asks after 24h
incubation was inoculated into 5dm3
of sterile growth
medium in a 7dm3
laboratory-scale fermenter
(Chemap AG10
). Air was sparged through a pipe
sparger placed below the bottom disc turbine (DT)
impeller and the pitched blade down ¯ow turbine
(PTD) used as an upper impeller at 250rpm with a gas
¯ow rate of 5dm3
minÀ1
. After 24h growth, the
medium was centrifuged at 17000Âg and 15°C for
15min (Beckman centrifuge model J2-MC).
B: Biotransformation using T delbrueckii
The cell mass obtained as described above was
aseptically inoculated into 5dm3
of biotransformation
medium in the fermenter using a peristaltic pump. The
reaction conditions described previously for this
biotransformation were used.10
The gas ¯ow rate
was 1.5dm3
minÀ1
. Impellers used in the study were
disc turbine (DT) as a lower impeller and pitched
blade down ¯ow turbine (PTD) as an upper impeller
at a speed of 250rpm. After the yeast had been
adapted for 1h in the biotransformation medium,
0.6% (w/v) of benzaldehyde and 0.6% (v/v) of
acetaldehyde (30±35%) were added aseptically and
the reaction continued for 2h. The experiment was
repeated three times and the average of each datum
point determined.
C: Analysis of biotransformation products
Analysis of the products of the biotransformation was
carried out by GC using a Chemito-8510 GC with
FID and Oracle-1 computing integrator. A 4m long
5% OV-17 column was used. The ¯ow rates of the N2
gas, H2 gas and air were 18, 20, and 200dm3
minÀ1
respectively. The temperature programming used was:
column temp 75°C for 3min, then heating at 10°C
minÀ1
up to 250°C and holding for 5min. The injector
temperature was 250°C and the detector temperature
was 265°C. The amount of sample injected was
2mm3
. The retention times of benzaldehyde, benzyl
alcohol, L-PAC and PAC-diol were 12.1min,
13.9min, 17.8min and 19.5min respectively. The
puri®cation of L-PAC was done by the method
described earlier.8
Step 2: Conversion of L-phenylacetylcarbinol (L-
PAC) (B) to 2-(methylimino)-1-phenyl-1-propanol (C)
L-PAC (obtained as above; 0.03 moles, 4.5g) was
placed in a 100cm3
round-bottom ¯ask containing
10cm3
of ethanol, cooled in crushed ice and the pH
adjusted to 4, by dropwise addition of conc HCl.
Threecm3
of a 40% (v/v) solution of methylamine was
added dropwise with constant stirring. The reaction
mixture was brought to ambient temperature
(30Æ2°C) and was irradiated for 3min at 50% power
in a modi®ed domestic microwave oven.11
The reac-
tion was further continued for 6min (two cycles of
3min at 50% power) with addition of 3cm3
40%
methylamine solution during each irradiation cycle.
After exposure to the microwaves, the reaction
mixture was cooled in crushed ice with 10cm3
of
added water. The pH of the reaction mixture was
adjusted to 4 and the reaction mixture was washed
with ether (25cm3
Â3) to collect unreacted L-PAC.
The aqueous layer was neutralized with NaHCO3 and
the pH value adjusted to between 7 and 8. The
aqueous layer was extracted with ether (25cm3
Â3)
and the combined ether layers were washed again with
15cm3
of cold water. The ether layer was dried by
passing through anhydrous sodium sulphate; ether was
removed in a rotavac to obtain the product (C) as a
yellow oil. This oil was further puri®ed by silica gel
(60±120 mesh) column chromatography using ethyl
acetate and toluene (6:4) as eluent.
Step 3: Reduction of
2-(methylimino)-1-phenyl-1-propanol (C) to
2-(methylamino)-1-phenyl-1-propanol (D)
(ephedrine)
The imine (2-(methylimine)-1-phenyl-1-propanol;
0.03 moles, 4.89g) was placed in a round-bottom
¯ask containing 10cm3
of ethanol. To this solution
NaBH4 (0.09 moles, 3.24g) was added in increments
of 0.02 moles for each microwave irradiation of 2min
at 50% power. The total reaction time under micro-
wave exposure was 10min (2min®ve cycles of 50%
power). After exposure to the microwaves, the reaction
mixture was cooled in ice and quenched by adding
10cm3
of ice-cold water and some pieces of ice. This
solution was then extracted with ether (25cm3
Â3).
The combined ether layers were washed twice with
138 J Chem Technol Biotechnol 77:137±140 (online: 2002)
VB Shukla et al
3. 15cm3
of cold water and dried by passing through
anhydrous sodium sulphate. The ether layer was
removed in a rotavac to give the oil containing product
and unreacted imine. The mixture was separated by
column chromatography using silica gel (60±120
mesh) and ethyl acetate±toluene (8:2) as eluent. The
isolated product obtained after elution of the column
was recrystallized in hot ethanol and dried to give
ephedrine. The biotransformation process using T
delbrueckii and the chemical process using microwave
irradiation is shown in Fig 1. Characterization of (B),
(C) and (D) was carried out using a Jasco-300 E
Spectrophotometer FT-IR as well as an Perkin-Elmer
IR Spectrophotometer (model 783) and expressed in
terms of wave number (cmÀ1
). The 1
H NMR spectra
were recorded in CDCl3 using a Bruker ACP-300
NMR. The chemical shifts are given in parts per
million using tetramethyl silane as internal standard.
RESULTS AND DISCUSSION
The biotransformation of benzaldehyde to L-PAC by
T delbrueckii yielded 458mg of L-PAC, 216mg of
benzyl alcohol, 2mg of PAC-diol and 4.5mg of
unreacted benzaldehyde per 100cm3
of the biotrans-
formation medium. The results of the biotransforma-
tion were found to be reproducible in the range of
Æ5%. The yield of L-PAC after the puri®cation was
19.5g, ie. 47%.
Step (2) of the reaction deals with condensation of a
keto group in L-PAC with that of the amino group of
methylamine to give an imine with loss of water
molecule. Synthesis of imine12,13
has been achieved by
using several reagents such as Brùnsted acids and
Lewis acids such as AlCl3, ZnCl2, TiCl4, or molecular
sieves and alumina etc. Verma et al14
carried out clay-
catalyzed synthesis of imines in solvent-less reaction
conditions under microwave irradiation and achieved
high yields of imines. In the present work, a homo-
geneous reaction medium such as ethanol was used for
carrying out condensation between L-PAC and methyl
amine under acidic conditions. It was observed that by
using microwaves this imine formation step was fast
and clean, giving satisfactory yields. The reaction was
repeated three times and was found to be reproducible
in the range of Æ2%. Since the yield of C reached 55%
in about 9min, beyond which time only a marginal
improvement in yield was observed, the optimized
time for microwave irradiation for this conversion was
taken as 9min (Fig 2). On puri®cation by column
chromatography the yield of C was 2.48g.
Step (3) involves reduction of the imine, ie carbon±
nitrogen double bond to give ephedrine. Many metal
hydrides have been reported to carry out such a
reduction.15
Varma and Dahiya16
have reported imine
reduction with NaBH4 supported on montmorillonite
K-10 clay under microwave irradiation in solvent-less
conditions with high yields of reduced product. In the
present work the reduction of imine was studied using
NaBH4 in ethanol. The optimal ratio of imine to
NaBH4 was 1:3 for reduction of imine (C) to
ephedrine (D). The reaction was repeated three times
and found to be reproducible in the range of Æ2%. In
the case of the reduction of imine to ephedrine the
optimum isolated yield of 64%, ie 3.11g, was obtained
in 10min of microwave irradiation. The time for
microwave irradiation was not increased further as
development of a brown coloration in the reaction
mixture resulted in the quality of the product being
affected (Fig 3).
The yields of the product and the characterization
by FT-IR and 1
H NMR for the products obtained in
the biotransformation and chemical transformation
are summarized in Table 1.
Figure 1. Scheme for ephedrine synthesis.
Figure 2. Optimization of L-phenylacetylcarbinol (L-PAC) to
2-(methylimino)-1-phenyl-1-propanol under microwave irradiation (Step 2).
Figure 3. Optimization for reduction of 2-(methylimino)-1-phenyl-1-
propanol to 2-(methylamino)-1-phenyl-1-propanol (ephedrine) under
microwave exposure (Step 3).
J Chem Technol Biotechnol 77:137±140 (online: 2002) 139
Production of Ephedrine using biotransformation and microwave oven
4. CONCLUSION
T delbrueckii biomass biotransformed benzaldehyde to
L-PAC, giving a yield of 458mg of L-PAC per 100cm3
of biotransformation medium. In a rapid two-step
process using microwave irradiation, the L-PAC was
readily converted to ephedrine. The two steps could be
completed within 19min under microwave irradiation.
In conclusion a unique combination of biotransforma-
tion and microwave assistance has been reported here
for the ®rst time for the synthesis of ephedrine.
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Table 1. Isolated yield percent with its FT-IR and 1
H NMR characterization of products obtained in biotransformation and chemical conversion
Product
Isolated
yield, % 1
H NMR (300MHz,CDCl3)d FT-IR (KBr), n cmÀ1
L-Phenylacetylcarbinol (L-PAC)
(B)
47 2.1 (s, 3H, CH3), 4.4 (broad s, 1H, OH), 5.1
(s, 1H, CH), 7.4±7.5 (m, 5H, Ar)
3458 (OÐH), 3030 (CÐH aromatic),
2925 (CÐH aliphatic), 1730 (C=O),
1597 (C=C aromatic), 749,697
(monosubstituted benzene)
2-(Methylimino)-1-phenyl-1-
propanol (C)
55 0.9±1 (s, 3H, CH3), 2.4 (s, 3H, CH3), 4.5
(broad s, 1H, OH), 4.8 (s, 1H, CH), 7.4±7.5
(m, 5H, Ar)
3357 (OÐH) 1644 (C=N)
2-(Methylamino)-1-phenyl-1-
propanol (ephedrine) (D)
64 0.9±1 (d, 3H, CH3), 2.3 (s, 3H, CH3), 2.9±3
(m, 1H, CH), 4.4 (broad s, 1H, OH),
4.8±4.9 (d, 1H, CH), 7.2±7.6 (m, 5H, Ar
and 1H, NH)
3433 (OÐH), 3048 (CÐH aromatic),
2925 (CÐH aliphatic), 1636 (NÐH
bending)
140 J Chem Technol Biotechnol 77:137±140 (online: 2002)
VB Shukla et al