1993 Fiscal Year Final Research Report Summary
Halogen-Exchange Fluorination of Aromatic Halides with HF or HF-Base
| Project/Area Number |
04650747
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
有機工業化学
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| Research Institution | Hokkaido University |
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Principal Investigator |
FUKUHARA Tsuyoshi Hokkaido Univi., Fac.of Engineering, Instructor, 工学部, 助手 (50238507)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Hydrogen fluoride / Halogen-exchange / Fluoroazines / SnAr mechanism / HF-organic base / Fluorine containing strong acid / Fluorine containing organic compound / 2,2-difluoroxazoline |
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| Research Abstract |
Heteroaromatic halides such as chloropyrimidines and halopyridines, chloroquinolines, 2-chlorobenzoxazole, 2-chlorobenzothiazole, or aromatic halides such as 2,4-dinitrochlorobenzene under went halogen-exchange fluorination with the treatement of HF or HF-base solutions to afford the corresponding fluorides in good yields. The reaction may be well explained to start by its initial protonation of nitrogen atom in the substrates. However, the addition of pyridine to HF was not effective for the halogen-exchange fluorination of 2-chloropyrimidine. On the contrary, increasing the amount of pyridine in HF hinders remarkably the halogen-exchange fluorination to be recovered by the substrate 2-chloropyrimidine almost exclusively. The reaction of substituted 2-chloropyridines and chloroquinolines also initiates the exchange fluorination of halogens with HF, which exist adjacent to N atom in the ring, affording the corresponding fluoride, in good yields.
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