The exhaustive reduction of formylporphyrins to methylporphyrins using dimethylformamide/water as reductant under microwave irradiation

2014 ◽  
Vol 18 (03) ◽  
pp. 200-208 ◽  
Author(s):  
Sarah J. Fletcher ◽  
Shannon R. Harper ◽  
Dennis P. Arnold
Keyword(s):  
Microwave Irradiation ◽  
Microwave Heating ◽  
Trifluoroacetic Acid ◽  
High Yield ◽  
Primary Alcohols ◽  
Visible Spectra ◽  
Added Water ◽  
Methyl Derivatives ◽  
Uv Visible ◽  
Derivatives Of

The reduction of meso-formyl derivatives of 5,15-diaryl- and 5,10,15-triphenylporphyrin (and their nickel(II) complexes) to the corresponding meso-methyl porphyrins is achieved in high yield by microwave heating of the substrate in dimethylformamide (DMF) in the presence of acids such as trifluoroacetic acid, or even just with added water. The reactions are complete in less than 30 min at 250 °C. The reaction is strongly suppressed in very dry DMF in the absence of added acid. The meso-hydroxymethyl porphyrins are also reduced to the methyl derivatives, suggesting the primary alcohols may be intermediates in the exhaustive reduction. UV-visible spectra taken at intervals during reaction at 240 °C indicated that at least one other intermediate is present, but it was not identified. In d7-DMF, the methylporphyrin isolated was mainly Por-CD2H, showing that both of the added hydrogens arise from the solvent, and not from the added water or acid.

Reaction of 5-Chloroalkyl-3-phenyl-4,5-dihydroisoxazoles with strong base. An unexpected new synthesis of the 2-Oxa-3-azabicyclo[3,1,0]hex-3-ene ring system

1977 ◽  
Vol 30 (8) ◽  
pp. 1855 ◽  
Author(s):  
TG Burrowes ◽  
WR Jackson ◽  
S Faulks ◽  
I Sharp
Keyword(s):  
Ring System ◽  
Dimethyl Sulphoxide ◽  
High Yield ◽  
Strong Base ◽  
Bicyclic Compounds ◽  
New Synthesis ◽  
Bicyclic System ◽  
Methyl Derivatives ◽  
High Yields ◽  
Derivatives Of

Reaction of 5-chloromethyl-3-phenyl-4,5-dihydroisoxazole with potassium t-butoxide in dimethyl sulphoxide gives 4-phenyl-2-oxa-3- azabicyclo[3,1,0]hex-3-ene in high yield and reaction of the 5-(1?- chloroethyl) homologue gives high yields of the diastereoisomeric 6- methyl derivatives of the bicyclic system. Some unsuccessful attempts to convert these bicyclic compounds into substituted cyclo-propanols and cyclopropenes are described.

A rapid solid supported synthesis of 4-amino-5-(pyridin-4-YL)-4H-1,2,4-triazol-3-thiol and its derivatives

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Solid State ◽  
Microwave Irradiation ◽  
Future Study ◽  
Biological Activities ◽  
Uv Visible ◽  
Anti Inflammatory ◽  
Derivatives Of

1,2,4-triazoles and its substituted derivatives were synthesized since these compounds are known for their excellent antibacterial, antifungal, anti-tubercular, antioxidant, anticancer, anti-inflammatory, analgesic, anticonvulsant and anxiolytic activities. 1,2,4-triazole and substituted derivatives of 1,2,4-triazole were synthesized using solid state microwave irradiation technique and synthesized compounds were characterized by UV-Visible, FTIR and GC-MS techniques and in future study the biological activities of synthesized compounds will be studied.

A comparative study of microwave versus conventional synthesis of lead phthalocyanine complexes

2005 ◽  
Vol 09 (12) ◽  
pp. 872-879 ◽  
Author(s):  
B. Narayana Achar ◽  
T. Manjappa Mohan Kumar ◽  
K. Sannegowda Lokesh
Keyword(s):  
Ir Spectroscopy ◽  
Microwave Irradiation ◽  
Conventional Heating ◽  
High Yield ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Conditions ◽  
Uv Visible ◽  
First Time ◽  
Very High

Lead(II) phthalocyanine (PbPc); lead(II) tetranitrophthalocyanine (PbTNP) and lead(II) tetraaminophthalocyanine (PbTAP) were synthesized in pure state by microwave irradiation and conventional heating methods. The procedures for their synthesis by the microwave technique are standardized and reported for the first time. PbPc and PbTNP were synthesized in dry conditions and PbTAP complex was synthesized in aqueous medium. All the compounds are obtained in very high yield (~90%). The synthesized complexes are characterized with respect to elemental analysis, UV-visible, IR-spectroscopy and X-ray diffraction study. The microwave methods are advantageous over the conventional method of synthesis with respect to higher yield, rapidity and simplicity.

scholarly journals Microwave-assisted multi-component synthesis of 3’-indolyl substituted pyrano[2,3-c]pyrazoles and their antimicrobial activity

2012 ◽  
Vol 77 (8) ◽  
pp. 983-991 ◽  
Author(s):  
Harshad Kathrotiya ◽  
Ranjan Patel ◽  
Manish Patel
Keyword(s):  
Antimicrobial Activity ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
High Yield ◽  
Pyrazole Derivatives ◽  
Human Pathogens ◽  
Broth Microdilution ◽  
E Coli ◽  
Microwave Assisted ◽  
Derivatives Of

A series of pyrano[2,3-c]pyrazole derivatives of indole has been synthesized by multi-component reaction using conventional and microwave irradiation approach. Particularly valuable features of this method include high yield, broad substrate scope, shorter reaction time and straightforward procedure. Antimicrobial screening against eight human pathogens, namely B. subtilis, C. tetani, S. pneumoniae, S. typhi, V. cholerae, E. coli, A. fumigatus and C. albicans by employing broth microdilution MIC method as recommended by NCCLS.

Methyl Violet Degradation by Bamboo Charcoal/Microwave Method

2013 ◽  
Vol 864-867 ◽  
pp. 1741-1744
Author(s):  
Na Li ◽  
Guo De Li ◽  
Wen Jie Pan ◽  
Nan Nan Zhang ◽  
Qi Liu ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Methyl Violet ◽  
Reaction Process ◽  
Microwave Method ◽  
Bamboo Charcoal ◽  
Microwave Irradiation Method ◽  
Visible Spectra ◽  
Speed Up ◽  
Uv Visible ◽  
Microwave Time

In the paper methyl violet degradation by bamboo charcoal-microwave irradiation method was researched. The main parameters which were studied including the amount of bamboo charcoal, H2O2dosage, FeSO4·7H2O dosage and time of microwave irradiation were investigated. The UV-visible spectra of methyl violet were determined. The results show that: under bamboo charcoal, H2O2and FeSO4·7H2O microwave condition the degeneration rate of methyl violet was almost 100%. The increase of bamboo charcoal dosage can accelerate the reaction process, speeding up the degradation of methyl violet. The increase of H2O2may provide more ·OH and speed up the reaction process, but when up to a certain amount, the influence is weakened. The lengthening of microwave time may enhance the reaction temperature, and urge the methyl violet to degrade completely. For 0.2 g·L-1methyl violet 4:9 diluted, by adding 0.5g bamboo charcoal, 1 mL 36% H2O2, 1 mL FeSO4·7H2O of 1mol·L-1and under mesotherm microwave for 30s, the methyl violet can be all degradated.

Physical Properties of TCNQ Salts with N-Methyl Derivatives of Pyridine

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik
Keyword(s):  
Physical Properties ◽  
Methyl Derivatives ◽  
Derivatives Of

Infrared and UV-visible spectra of layer semiconductors Gas, GaSe and GaTe

1977 ◽  
Vol 38 (10) ◽  
pp. 1293-1299 ◽  
Author(s):  
U. Giorgianni ◽  
G. Mondio ◽  
P. Perillo ◽  
G. Saitta ◽  
G. Vermiglio
Keyword(s):  
Visible Spectra ◽  
Uv Visible

Polymer-Bound Triphenylphosphine and 4,4′-Dinitroazobenzene as a Coupling Reagents for Chromatography-Free Esterification Reaction

2019 ◽  
Vol 16 (7) ◽  
pp. 1024-1031
Author(s):  
Diparjun Das ◽  
Kalyani Rajkumari ◽  
Lalthazuala Rokhum
Keyword(s):  
Microwave Irradiation ◽  
Solid Phase ◽  
Reaction System ◽  
Triphenylphosphine Oxide ◽  
High Yield ◽  
Sustainable Chemistry ◽  
Esterification Reaction ◽  
Coupling Reagent ◽  
Simple Filtration ◽  
Esterification Reactions

Aim and Objective: Sustainable production of fine chemicals both in industries and pharmaceuticals heavily depends on the application of solid-phase synthesis route coupled with microwave technologies due to their environmentally benign nature. In this report, a microwave-assisted esterification reaction using polymer-bound triphenylphosphine and 4,4′-dinitroazobenzene reagent system was investigated. Materials and Methods: The solvents were obtained from Merck India. Polymer-bound triphenylphosphine (~3 mmol triphenylphosphine moiety/g) was acquired from Sigma-Aldrich. The progress of the reaction was observed by thin-layer chromatography. All the reactions were performed in Milestones StartSYNTH microwave. The NMR spectra were recorded on Bruker Avance III 300, 400, and 500 MHz FT NMR Spectrometers. Using azo compound and polymer-bound triphenyl phosphine as a coupling reagent, esterification of different carboxylic acids with alcohols was performed under microwave irradiation. Results: Esterification of benzoic acid with 1-propanol under microwave irradiation gave a high yield of 92% propyl benzoate in 60 minutes only. Isolation of the ester products was relatively simple as both the byproducts polymer-bound triphenylphosphine oxide and hydrazine could be removed by simple filtration. The rates of reactions were found to be directly proportional to the pKa of the benzoic acids. Conclusion: 4,4′-Dinitroazobenzene was introduced as a novel coupling reagent, in conjugation with polymer-bound triphenylphosphine, for esterification reactions under microwave irradiation. The low moisture sensitivity of the reaction system, easy separation of the byproducts, and column chromatographyfree isolation of esters help our methods with application significance, particularly from the ‘Sustainable Chemistry’ perspective.

Microwave-assisted Synthesis of Benzoxazoles Derivatives

2020 ◽  
Vol 7 (3) ◽  
pp. 183-195
Author(s):  
Musa Özil ◽  
Emre Menteşe
Keyword(s):  
Microwave Irradiation ◽  
Reaction Medium ◽  
Pharmaceutical Chemistry ◽  
Conventional Heating ◽  
High Yield ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Optical Brighteners ◽  
Chemistry Research ◽  
Extensive Class

Background: Benzoxazole, containing a 1,3-oxazole system fused with a benzene ring, has a profound effect on medicinal chemistry research owing to its important pharmacological activities. On the other hand, the benzoxazole derivative has exhibited important properties in material science. Especially in recent years, microwave-assisted synthesis is a technique that can be used to increase diversity and quick research in modern chemistry. The utilization of microwave irradiation is beneficial for the synthesis of benzoxazole in recent years. In this focused review, we provide a metaanalysis of studies on benzoxazole in different reaction conditions, catalysts, and starting materials by microwave technique so far, which is different from conventional heating. Methods: Synthesis of different kind of benzoxazole derivatives have been carried out by microwave irradiation. The most used method to obtain benzoxazoles is the condensation of 2-aminophenol or its derivatives with aldehydes, carboxylic acids, nitriles, isocyanates, and aliphatic amines. Results: Benzoxazole system and its derivatives have exhibited a broad range of pharmacological properties. Thus, many scientists have remarked on the importance of the synthesis of different benzoxazole derivatives. Conventional heating is a relatively inefficient and slow method to convey energy in orientation to the reaction medium. However, the microwave-assisted heating technique is a more effective interior heating by straight coupling of microwave energy with the molecules. Conclusion: In this review, different studies were presented on the recent details accessible in the microwave- assisted techniques on the synthesis of the benzoxazole ring. It presents all examples of such compounds that have been reported from 1996 to the present. Benzoxazoles showed an extensive class of chemical substances not only in pharmaceutical chemistry but also in dyestuff, polymer industries, agrochemical, and optical brighteners. Thus the development of fast and efficient achievement of benzoxazoles with a diversity of substituents in high yield is getting more noteworthy. As shown in this review, microwave-assisted synthesis of benzoxazoles is a very effective and useful technique.

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