scholarly journals Acid-Promoted Synthesis of Imidazolyl-Pyrazole Derivatives via a Multicomponent Reaction Using Ultra Sound Irradiation

2014 ◽  
Vol 30 ◽  
pp. 277-283
Author(s):  
Denish J. Viradiya ◽  
Vipul C. Kotadiya ◽  
Rajesh Kakadiya ◽  
Anamik Shah
Keyword(s):  
Acetic Acid ◽  
Mass Spectroscopy ◽  
Multicomponent Reaction ◽  
High Purity ◽  
Ammonium Acetate ◽  
Analytical Techniques ◽  
Ultra Sound ◽  
Pyrazole Derivatives ◽  
Heterocyclic Aldehyde ◽  
C Nmr

Some new imidazolyl pyrazole derivatives have been synthesized using benzil, ammonium acetate, and heterocyclic aldehyde in ethanol and acetic acid under ultra sound irradiation. The obtained products using this approach are having high purity and good in yield. By conducting the reactions in ethanol, the solid products were precipitated out and could be isolated simply by filtration. The synthesized compounds were characterized by various analytical techniques such as 1H and 13C NMR and further supported by mass spectroscopy.

One-Pot Synthesis of Functionalised 4-Spiro-1,4-Dihydropyridines Via [1+2+1+2]-Cyclisation

2017 ◽  
Vol 41 (9) ◽  
pp. 513-516 ◽  
Author(s):  
Pan Zhou ◽  
Biao Hu ◽  
Lingling Lu ◽  
Rong Huang ◽  
Fuchao Yu
Keyword(s):  
Acetic Acid ◽  
Ammonium Acetate ◽  
Water Solution ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Approach ◽  
H Nmr ◽  
Three Component Reaction ◽  
C Nmr ◽  
Operational Simplicity

A simple and efficient approach for the synthesis of 4-spiro-1,4-DHP derivatives has been developed, involving one-pot three-component reaction of isatins, N,N-dimethylenaminones with ammonium acetate in EtOH–water solution promoted by acetic acid. Compared with the previous [1+2+3]-cyclisation method, this [1+2+1+2]-cyclisation procedure has advantages as it is more environmentally friendly, has easier operational simplicity, and requires milder reaction conditions. Moreover, these novel compounds have been obtained in moderate to good yields and their structures have been confirmed by 1H NMR, 13C NMR and IR and HRMS spectroscopy.

Reaction of O-Alkyl-N-substituted Iminothiocarbonates with Bromoacetyl Bromide. A General Method for the Synthesis of 3-Substituted 1,3-Thiazolidine-2,4-diones

1996 ◽  
Vol 61 (3) ◽  
pp. 432-436 ◽  
Author(s):  
Ján Imrich ◽  
Juraj Bernát ◽  
Pavol Kristian ◽  
Tatiana Bušová ◽  
Slávka Hočová
Keyword(s):  
Mass Spectroscopy ◽  
High Purity ◽  
Sodium Salts ◽  
H Nmr ◽  
Independent Synthesis ◽  
General Method ◽  
C Nmr

Reaction of sodium salts of O-methyl-N-substituted iminothiocarbonates with bromoacetyl bromide represents a new general method for preparation of 3-substituted 1,3-thiazolidine-2,4-diones in good yields and high purity. The structure of the synthesized products has been confirmed by 1H NMR, 13C NMR, IR and mass spectroscopy as well as by independent synthesis.

Synthesis of Pyrazole Analogs from Argentatin B

1995 ◽  
Vol 60 (4) ◽  
pp. 612-618 ◽  
Author(s):  
Roberto Martínez ◽  
Elda Limón ◽  
María del R. Arellano ◽  
Mariano Martínez ◽  
Marco Brito
Keyword(s):  
Mass Spectroscopy ◽  
Pyrazole Derivatives ◽  
C Nmr

The pyrazole derivatives 3'-(2-R-phenyl)[3,2-c]pyrazole-16,24-epoxy-25-hydroxy-9 ,19-cyclostane Va - Vf have been prepared in a three step reaction from argentatin B. The structure of all the compounds synthesized was corroborated by 1H and 13C NMR, IR and mass spectroscopy.

Instant 99mTc Compounds

1971 ◽  
Vol 10 (03) ◽  
pp. 245-251 ◽  
Author(s):  
P. Richards ◽  
W. C. Eckelman
Keyword(s):  
Physical Properties ◽  
High Purity ◽  
Analytical Techniques ◽  
Full Potential ◽  
Labeled Compounds ◽  
Ph Adjustment ◽  
One Step ◽  
Stannous Ion ◽  
99Mtc Radiopharmaceuticals ◽  
Potential Use

SummaryThe full potential use of technetium has not been achieved despite its ideal physical properties, dosimetry and availability because of the complex preparations required for 99mTc radiopharmaceuticals. One of the goals of our work is to develop techniques for the preparation of high-purity 99mTc compounds which can be easily prepared, ideally by adding pertechnetate to a prepared solution.The use of stannous ion as reducing agent for technetium makes it possible to obtain such one-step, high-purity products. All non-radioactive components can be premixed in a single vial before addition of the radioactive pertechnetate. No final pH adjustment, further chemical manipulation or purification is required.Procedures for two instantly labeled compounds have been developed to date: 99mTc DTPA and 99mTc HSA. The 99mTc DTPA is prepared by adding pertechnetate to a previously prepared solution of stannous ion and CaNa3 DTPA which has been stored at pH 4. The 99mTc HSA is prepared by adding pertechnetate to a solution of stannous ion and HSA. The parametric variations and analytical techniques involved in formulating these procedures are described. It appears that development of kits for other biologically interesting compounds may be possible using similar procedures.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Vapour-liquid equilibrium in the ternary system cyclohexane-acetic acid-propionic acid

1989 ◽  
Vol 54 (11) ◽  
pp. 2840-2847 ◽  
Author(s):  
Ivona Malijevská ◽  
Alena Maštalková ◽  
Marie Sýsová
Keyword(s):  
Acetic Acid ◽  
Ternary System ◽  
Propionic Acid ◽  
Activity Coefficients ◽  
Error Propagation ◽  
Analytical Techniques ◽  
Liquid Equilibrium ◽  
Consistency Test ◽  
Propagation Law ◽  
Equilibrium Data

Isobaric equilibrium data (P = 101.3 kPa) for the system cyclohexane-acetic acid-propionic acid have been measured by two different analytical techniques. Activity coefficients calculated by simultaneous solving of equations for the chemical and phase equilibria were subjected to a consistency test based on inaccuracies determined from the error propagation law, and were correlated by Wilson’s equation. The activity coefficients measured were compared with those calculated from binary vapour-liquid equilibrium data and with values predicted by the UNIFAC method.

Acetic acid mediated regioselective synthesis of 2,4,5-trisubstituted thiazoles by a domino multicomponent reaction

2019 ◽  
Vol 43 (22) ◽  
pp. 8644-8650 ◽  
Author(s):  
Mohit Saroha ◽  
Jitender M. Khurana
Keyword(s):  
Acetic Acid ◽  
Multicomponent Reaction ◽  
Regioselective Synthesis ◽  
Domino Reaction ◽  
Thiazole Derivatives ◽  
Active Methylene

Acetic acid mediated regioselective synthesis of novel 2,4,5-trisubstituted thiazole derivatives has been reported by a domino reaction of thiosemicarbazide and aldehydes/ketones/isatin, to generate thiosemicarbazones (in situ) followed by addition of arylglyoxal and active methylene/activated C–H acids/pyrazole/indole in ethanol at 80 °C.

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