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Efficient One-Pot Synthesis of Benzo[e]pyrazolo[1,5-c][1,3]thiazine Derivatives under Copper-Catalyzed Conditions
| Content Provider | Semantic Scholar |
|---|---|
| Author | Yang, Xiaobo Jie, Jiyang Li, Haoyi Piao, Meihui |
| Copyright Year | 2016 |
| Abstract | An efficient method has been developed for the synthesis of benzo[e]pyrazolo[1,5-c][1,3]thiazines via one-pot two-step reactions of readily available substituted 1-(2-halophenyl)-3-akylprop-2-yn-1-ones, hydrazine hydrochloride and β-oxodithioesters under mild conditions, and the corresponding benzo[e]pyrazolo[1,5-c][1,3]thiazines were obtained in good to excellent yields. The novel method affords a new strategy for the construction of diverse and useful poly N,S-heterocyclic compounds. INTRODUCTION N-Heterocycles and S-heterocycles play the key roles in pharmaceutical and agrochemical industries.1,2 Pyrazoles represent an important structural motif frequently found in man-made biologically active compounds such as celecoxib, fipronil, lonazolac, viagra, although they are rarely found in natural products.3 Thiazine derivatives show various biological and medical functions.4 For example, they exhibit antibacterial,5 anntimalarial,6 antiretroviral activities,7 and some of them are investigated as cell growth inhibitors,8 promising inhibitors of nitric oxide synthase,9 endogenous natriuretic factors.10 However, methods for the synthesis of pyrazolothiazines are very limited.11 Additionally, dithioester was a good partner when some S-heterocycles were synthesized.12 So, it provides us opportunities for developing novel procedures for the synthesis of this kind of derivatives. In our previous works, we successfully employed 1-(2-halophenyl)-3-arylprop-2-yn-1-ones, hydrazine hydrochloride and other nitrogen sources to construct N-fused heterocycles under mild copper-catalyzed conditions (Scheme 1).13-15 And we found that pyrazoles could be easily constructed by 1-(2-halophenyl)-3-arylprop-2-yn-1-ones and hydrazine hydrochloride. Following this strategy, we herein wish to report a convenient and efficient one-pot synthesis of pyrazolothiazines under copper-catalyzed conditions. HETEROCYCLES, Vol. 92, No. 7, 2016 1215 |
| Starting Page | 1215 |
| Ending Page | 1215 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| DOI | 10.3987/COM-16-13477 |
| Volume Number | 92 |
| Alternate Webpage(s) | http://wxjs.chinayyhg.com/upload/Files/20161128225350851/1215-1223.pdf |
| Alternate Webpage(s) | https://doi.org/10.3987/COM-16-13477 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
