Journal ArticleDOI
Synthesis and reactions of N-substituted pyrazolo-3-sulfolenes
Ta-Shue Chou,Ruei-Chih Chang +1 more
TLDR
In this article, N-Toluenesulfonyl- and N-(anilinocarbonyl)pyrazolo-3-sulfolenes have been prepared from the protected oxotetrahydrothiophene carbaldehyde via a sequence of hydrazone formation, ketal hydrolysis, cyclization, dehydration, and oxidation reactions.Abstract:
N-Toluenesulfonyl- and N-(anilinocarbonyl)pyrazolo-3-sulfolenes have been prepared from the protected oxotetrahydrothiophenecarbaldehyde (7) via a sequence of hydrazone formation, ketal hydrolysis, cyclization, dehydration, and oxidation reactions. These N-substituents migrate between the two nitrogen atoms of the pyrazole ring at different stages. Extrusion of SO 2 from N-anilinocarbonylpyrazolo-3-sulfolenes was achieved at 180-200°C and the transient intermediate, the pyrazolo-o-quniodimethane, could be trapped with dienophilesread more
Citations
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Journal ArticleDOI
o-Quinodimethanes: Efficient Intermediates in Organic Synthesis.
José L. Segura,Nazario Martín +1 more
Journal ArticleDOI
Generation and chemical reactions of quinoxalino-o-quinodimethane
Ta-Shue Chou,Chung-Wen Ko +1 more
TL;DR: In this article, the quinoxalino-3-sulfolene 7 was prepared via two convenient routes and discovered its unusual stability toward thermal extrusion of SO2. But this was at temperatures higher than 290 °C.
Journal ArticleDOI
Preparation and Reactions of Benzofurano-, Indolo-, and Benzothieno-3-sulfolenes
Chung-Wen Ko,Ta-Shue Chou +1 more
TL;DR: In this paper, the precursors of 3-sulfolenes bearing bromo or alkyl group substitution from which substituted heteroaromatic o-quinodimethanes are generated have also been synthesized.
Book ChapterDOI
Chapter 2 Heterocyclic ortho-quinodimethanes
TL;DR: This chapter presents an overview of Quinodimethane and derivatives chemistry and methods of generation, and intends to stimulate the use of these species in synthesis.
Patent
1- Aryl-3-thioalkyl pyrazoles, the synthesis thereof and the use thereof as insecticides
Daljit S. Dhanoa,Dario Doller,Sanath K. Meegalla,Richard M. Soll,Nancy Wisnewski,Gary M. Silver,Dan T. Stinchcomb,R. Lee Seward,Dimitris K. Agrafiotis,Deyou Sha +9 more
TL;DR: In this article, the pyrazole derivatives have Formula (I) or as salt thereof, where R1 represents R?5O, R5SO?2, R? 5SO or R5?S in which R5 is as defined herein; X is halo, cyano, C?1-6? alkoxycarbonyl, C2-6 alkynyl, optionally substituted C6-14 aryl or an optionally substituted 5- to 7- membered heteroaromatic ring linked to thiazole via a carbon-carbon bond
Related Papers (5)
A novel route to the preparation of pyrazole analogs of o-xylylene.
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