GEWALD REACTION PDF

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophenecarbonitrile functionality. The Gewald reaction is a very useful and versatile method for condensation of aliphatic aldehyde or ketone or β-dicarbonyl compound with active nitrile and. The Gewald reaction is an organic reaction involving the condensation of a ketone (or aldehyde when R2 = H) with a α-cyanoester in the presence of elemental.

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Conclusions In this review we have extended the problems of synthesis of variety of substituted 2aminothiophenes and their scope and utilization. Deprotection of tertbutoxycarbonyl group resulted directly to ring closure of the intermediates isothiocyanatothiophenecarboxylic acids leading directly rdaction 64a,b.

Gewald reaction: synthesis, properties and applications of substituted 2-aminothiophenes

Pharmazie51, 7. Even though 2-substituted thiazoles are important structures in their own right, further substitution can gewapd easily achieved through published protocols to form 2,4-substituted thiazoles, 2,5-substituted thiazoles and also 2,4,5-substituted thiazoles [30].

Starting from substituted 2-aminothiophenes 36a-c, the target fused heterocyclic derivatives 39a-c was prepared in a four step reaction sequence. The first report on the development and the use of substituted 2-aminothiophenes and the Gewald reaction was published by authors. As it is presented on Schemesthe substituted 2-aminothiophene ring is formed from the aliphatic starting substrates during the multi step reaction sequence: Most of the published Gewald synthetic procedures required long reaction times varying between 4 and reactioj h.

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Also, substrate 46lacking an acidic proton, was recovered unchanged from the reaction. Her scientific achievements are focused on the synthesis of new heterocyclic compounds. The most suitable base for the activation with sulfur and the subsequent sulfur addition morpholine has been proved. Synthesis of substituted 2-aminothiophenes via Gewald reaction 2.

Microwave enhanced Gewald reaction in combination with solid-support accelerated method was presented as an easy access to polysubstituted 2-aminothiophenes.

Several geaction have already been described for the synthesis of substituted thiazoles and yewald [].

Introduction Results and Discussion Screening for the bifurcation conditions Optimisation and scoping of thiazole gewsld Conclusion Reactoon Supporting Information Acknowledgements References. Scheme 15 Table 9. The replacement of phenyl isothiocyanate by other commercially available ones decreases dramatically the yields of thiophenes News The updated journal statistics include the impact factor and alternative journal metrics. During her doctoral studies she joined the group of researchers at School of Chemistry at Dublin City University, Ireland and her postoctoral fellowship was held at Research Center for Gewa,d and Advanced Material of Jagiellonian University, Krakow, Poland, both within Marie-Curie actions dealing with chemistry and physics of coordination compounds.

The latter conditions were then chosen to progress due to the increased productivity based upon the higher concentration and slightly shorter reaction time.

Applications of substituted 2-aminothiophenes in drug design, optoelectronics and dyes 4. Particular attention is given to studies published in the previous years. The advantage of this process is in possibility of the prediction of hydrophilic or hydrophobic character of final structures with right choice of starting substrates bearing functional groups.

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The study demonstrates the versatility of 2-aminothiophenes as a synthetic entry to serine protease-inhibiting, fused 1,3-oxazinones. In Purinergic Approaches in Experimental Therapeutics, ed.

Gewald Reaction

Results from his work have been published in about peer-reviewed scientific papers and 62 patents. Cyril and Methodius in Trnava as Chair of the Department of Chemistry, where she holds a position of an emeritus professor nowadays.

Consequently, expanding the scope of thiazole synthesis by developing new methodologies remains an active area of research. However, the alternative mechanism for the thiazole formation as described herein has not previously been reported and initially presented some queries. The review starts with an extensive introduction that discusses the most multidisciplinary areas of 2-aminothiophene research with inputs from medicine, pharmacology, chemistry, biology, biochemistry, materials science and physics.

Synthetic strategies and new reactions, structure-property relationships, self- assembling properties and applications in organic electronics, solar cells and fotoionisation of water with visible lights are main highligts of his research. Kemi16, Synthesis44, — US Patent NoOctober As was reported in, the facile one-pot synthesis of polysubstituted thiophenes and thieno[2,3-b]thiophenes was completed through cyclization of a-oxo ketene S,S -acetals.

Conversion of formed ester 58 to final 3-deazathiamine 61 was accomplished in four subsequent steps isolating the crucial intermediates — aldehyde 59 and nitrile