Synthesis of 4-Phenylselenyl-1h-pyrazoles by electrophilic cyclization

Download

index.pdf

Date

2011

Author

Demirci, Deniz

Metadata

Show full item record

Item Usage Stats

97
views

30
downloads

In this study, the synthesis of 5-ferrocenyl/aryl-4-(phenylselenyl)-1H-pyrazole derivatives was investigated since the integration of ferrocenyl and selenium moieties into pyrazole derivatives may increase their current biological activities. Initially, the starting propargyl aldehydes were synthesized from corresponding acetylenes. Subsequently, propargyl aldehydes were reacted with hydrazines to yield corresponding hydrazones. Then the in situ synthesized hydrazones were subjected to electrophilic cyclization with phenylselenyl chloride, which afforded 5-ferrocenyl/aryl-4-(phenylselenyl)-1H-pyrazoles in one-pot manner. Subsequently, reaction conditions were optimized in terms of electrophile, base, temperature and solvent. Best results were obtained with phenylselenyl chloride and NaHCO3 at room temperature in DCM for ferrocenyl substituted pyrazoles and DCE for aryl substituted pyrazoles. In summary, by employing the electrophilic cyclizations of in situ synthesized acetylenic hydrazones, a variety of 5-ferrocenyl/aryl-4-(phenylselenyl)-1H-pyrazole derivatives were synthesized in one-pot way in moderate to good yields.

Subject Keywords

CChemistry, Organic

URI

http://etd.lib.metu.edu.tr/upload/12613910/index.pdf
https://hdl.handle.net/11511/20841

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

OXIDATION OF ARYL ALKYL KETONES TO ALPHA-ACYLOXY, ALPHA-(CAMPHORSULFONYLOXY), OR ALPHA-HYDROXY DERIVATIVES USING MANGANESE(III) ACETATE IN COMBINATION WITH CARBOXYLIC-ACIDS OR (1S)-(+)-10-CAMPHORSULFONIC ACID DEMIR, AS; CAMKERTEN, N; AKGUN, H; Tanyeli, Cihangir; MAHASNEH, AS; WATT, DS (Informa UK Limited, 1990-01-01) The α-oxidation of aryl alkyl ketones using manganese(III) acetate in the presence of various carboxylic acids and (1S)-(+)-10-camphorsulfonic acid provided a convenient synthesis of α-acyloxy, α-(10-camphorsulfonyloxy), and α-hydroxy derivatives in good yield.
Synthesis of beta-chloro-alpha-aminophosphonate derivatives via the regioselective ring opening of unactivated aziridine-2-phosphonates Polat-Cakir, Sidika; BEKSULTANOVA, Nurzhan; Doğan, Özdemir (Informa UK Limited, 2018-12-02) A series of unactivated racemic and chiral aziridine-2-phosphonates were synthesized by modified Gabriel-Cromwell reaction. Ring opening reaction of the synthesized phosphonates by gaseous HCl provided access to a wide range of biologically interesting novel beta-chloro-alpha-aminophosphonates. All reactions toward each of the above-mentioned products can be conducted regioselectively in high yields.
Synthesis and reactions of alpha-keto-beta-hydroxyphosphonates Barış, Şehriban; Demir, Ayhan Sıtkı; Department of Chemistry (2007) This thesis presents synthesis and different reactions of alpha-keto-beta-hydroxyphosphonates. Toward this aim, the hydroxyl functionality of alpha-hydroxycarboxylic acids were protected with alkyl or acyl groups and then formation of acid chloride followed by the reaction with trialkylphosphite furnished protected alpha-keto-beta-hydroxyphosponates. Nucleophilic addition reactions were applied to these compounds to obtain quaternary alcohols with phosphonate functionality. The addition reactions were tried...
Synthesis of 1,2,3,5- tetrasubstituted pyrrole derivatives via 5-exo-dig type cyclization and stereoselective functionalisation of ferrocene derivatives Kayalar, Metin; Demir, Ayhan Sıtkı; Department of Chemistry (2005) A convenient and new method for the synthesis of 1,2,3,5-tetrasubstituted pyrrole derivatives starting from 1,3,-dicarbonyl compounds through acid catalyzed cyclization reaction is described. Alkylation of 1,3-dicarbonyl compound with propargyl bromide followed by one step cyclization with the introduction of primary amines in the presence of catalytic amount of triflouroacetic acid (TFA) affords the corresponding pyrrole derivatives in high yields. The investigations on the studies of developing a new meth...
Synthesis of chiral lactones via the baeyer villiger oxidation of cyclic aromatic acetoxy ketones novel annulation reactions of 2-propynyl-1,3-dicarbonyl compounds to form pyrroles addition of acyl phosphonates to diethyl cyanophosphonate (depc) Aybey, Asuman; Demir, Ayhan Sıtkı; Department of Chemistry (2009) Chiral Baeyer-Villiger (BV) oxidation of cyclic ketones allows rapid access to asymmetric lactones as valuable intermediates in organic chemistry and frequently encountered precursors in enantioselective synthesis. In the first part, BV oxidation of functionalized ketones, especially cyclic -hydroxy and acetoxy ketones is described which could be a straightforward route to the -hydroxy lactones and -hydroxyalkanoic acid derivatives. The -acetoxylation of indanone, tetralone and chromanone derivatives by usi...

Citation Formats

D. Demirci, “Synthesis of 4-Phenylselenyl-1h-pyrazoles by electrophilic cyclization,” M.S. - Master of Science, Middle East Technical University, 2011.