Synthesis of pyridazino(4,5-e)(1,3,4)thiadiazines and the ring contraction to pyrazolo(3,4-d)pyridazines through extrusion of sulfur.
抄録
Cyclization of 2-substituted 5-[(α-bromobenzylidene) hydrazino)]-4-chloro-3 (2H)-pyridazinones (2) with potassium thioacetate, followed by deacetylation, provided new ring system derivatives, 7-substituted 2-phenyl-4H-pyridazino [4, 5-e] [1, 3, 4] thiadiazin-8 (7H)-ones (4). 8-Chloro and 8-amino derivatives (10) of the pyridazinothiadiazine ring were readily derived from 4-acetyl-2-phenyl-4H-pyridazino [4, 5-e] [1, 3, 4] thiadiazin-8 (7H)-one (3d) by chlorination and subsequent amination. Ring contraction of the 8-oxo derivatives (4) to 5-substituted 3-phenyl-1H-pyrazolo [3, 4-d] pyridazin-4 (5H)-ones (6), through extrusion of sulfur under basic or thermal conditions, was observed. A similar reaction occurred in the case of the 8-chloro and 8-amino derivatives (10). Probable mechanisms for these reactions and differences of reactivity between 4 and 10 are discussed.
収録刊行物
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- CHEMICAL & PHARMACEUTICAL BULLETIN
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CHEMICAL & PHARMACEUTICAL BULLETIN 32 (11), 4437-4446, 1984
公益社団法人 日本薬学会
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詳細情報 詳細情報について
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- CRID
- 1390001204165542400
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- NII論文ID
- 130003769512
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- COI
- 1:CAS:528:DyaL2MXhvVGjsbk%3D
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- ISSN
- 13475223
- 00092363
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- 本文言語コード
- en
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- データソース種別
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- JaLC
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- 抄録ライセンスフラグ
- 使用不可