A Convenient Synthesis of 2,3-Dihydro-4 H -thiopyrano[2,3- b ]-, -[2,3- c ]-, or -[3,2- c ]pyridin-4-ones by the Reaction of the Corresponding 1-(Chloropyridinyl)alk-2-en-1-ones with NaSH | Health & Environmental Research Online (HERO)

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Citation
Tags

HERO ID

8228046

Reference Type

Journal Article

Title

A Convenient Synthesis of 2,3-Dihydro-4 H -thiopyrano[2,3- b ]-, -[2,3- c ]-, or -[3,2- c ]pyridin-4-ones by the Reaction of the Corresponding 1-(Chloropyridinyl)alk-2-en-1-ones with NaSH

Author(s)

Kobayashi, K; Imaoka, A; ,

Year

2013

Is Peer Reviewed?

Yes

Journal

Helvetica Chimica Acta
ISSN: 0018-019X

Publisher

WILEY-V C H VERLAG GMBH

Location

WEINHEIM

Page Numbers

624-632

DOI

10.1002/hlca.201200543

Web of Science Id

WOS:000317492200005

URL

https://onlinelibrary.wiley.com/doi/10.1002/hlca.201200543
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Abstract

2,3-Dihydro-4H-thiopyrano[2,3-b]pyridin-4-ones 4 were prepared by a three-step sequence from commercially available 2-chloropyridine (1). Thus, successive treatment of 1 with (Pr2NLi)-Pr-i (LDA) and alpha,beta-unsaturated aldehydes gave 1-(2-chloropyridin-3-yl)alk-2-en-1-ols 2, which were oxidized with MnO2 to 1-(2-chloropyridin-3-yl)alk-2-en-1-ones 3. The reactions of 3 with NaSH center dot n H2O proceeded smoothly at 0 degrees in DMF to provide the desired thiopyranopyridinones. Similarly, 2,3-dihydro-4H-thiopyrano[2,3-c]pyridin-4-ones 8 and 2,3-dihydro-4H-thiopyrano[3,2-c]pyridin-4-ones 12 were obtained starting from 3-chloropyridine (5) and 4-chloropyridine (9), respectively.