Synthesis of [2‐(Trimethylsilyl)ethynyl]pyrazoles Based on Bis(trimethylsilyl)acetylene and Arylacetyl Chlorides
- 7 September 2012
- journal article
- research article
- Published by Wiley in European Journal of Organic Chemistry
- Vol. 2012 (30) , 5965-5971
Abstract
A practical approach to the synthesis of [2‐(trimethylsilyl)ethynyl]pyrazoles was developed through condensation of hydrazines with enynones that are easily accessible frombis(trimethylsilyl)acetylene and arylacetyl chlorides. Optimized conditions for reactions with monoarylhydrazines permit the chemoselective formation of 5‐alkynylpyrazoles in high yields (48–94 %). When monoalkylhydrazines or the parent hydrazine is used, mixtures of 3‐ and 5‐alkynylpyrazoles are formed in 73–79 % yields. The method uses inexpensive starting materials and can be applied to a variety of substrates, which makes it convenient for the synthesis of alkynylpyrazoles.Keywords
This publication has 29 references indexed in Scilit:
- Synthesis and biological evaluation of substituted pyrazoles as blockers of divalent metal transporter 1 (DMT1)Bioorganic & Medicinal Chemistry Letters, 2012
- Synthesis of Simple Diynals, Diynones, Their Hydrazones, and Diazo Compounds: Precursors to a Family of Dialkynyl Carbenes (R1—C≡C—C̈—C≡C—R2)The Journal of Organic Chemistry, 2010
- Syntheses and Phosphorescent Properties of Blue Emissive Iridium Complexes with Tridentate Pyrazolyl LigandsInorganic Chemistry, 2008
- Synthesis, Optical Properties, and Characterization of New Soluble Conjugated Poly(p-phenylenevinylene) Derivatives Constituted of Alternating Pyrazole and 1,3,4-Oxadiazole MoietiesAustralian Journal of Chemistry, 2008
- Pyrazoles2008
- Blue-Emitting Platinum(II) Complexes Bearing both Pyridylpyrazolate Chelate and Bridging Pyrazolate Ligands: Synthesis, Structures, and Photophysical PropertiesInorganic Chemistry, 2007
- Diaryl substituted pyrazoles as potent CCR2 receptor antagonistsBioorganic & Medicinal Chemistry Letters, 2007
- Synthesis of linked heterocycles via use of bis-acetylenic compoundsTetrahedron Letters, 2006
- Practical routes to diacetylenic ketones and their application for the preparation of alkynyl substituted pyridines, pyrimidines and pyrazolesTetrahedron, 2003
- Synthesis of a new analogue of BINOL based on a homodimer of substituted 1-hydroxypyrazoleJournal of the Chemical Society, Perkin Transactions 1, 2001