Abstract
The thermal cyclization of 2‐alkynylbenzenediazonium salts 2 known as the Richter reaction and leading, as described in the literature, only to 4‐hydroxycinnolines 6 has been studied. A new probable route to these compounds involving intermediate formation of the 4‐chlorocinnolines 4 followed by hydrolysis of the latter to 6 is discussed. A new understanding of the reaction mechanism has induced us to change the reaction conditions in order to synthesize some 4‐bromo‐ (5), 4‐chloro‐ (4), and 4‐hydroxycinnolines 6 as well as 4‐bromo‐(8b) and 4‐chloropyrazolopyridazine 8a.
Original language | English |
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Pages (from-to) | 775-779 |
Number of pages | 5 |
Journal | Liebigs Annalen |
Volume | 1995 |
Issue number | 5 |
DOIs | |
Publication status | Published - 24 Apr 1995 |
Externally published | Yes |
Keywords
- 2‐Diazotolanes
- Cinnolines
- Diazotization
- Pyrazolopyridazines
- Richter reaction
- Tolanes
ASJC Scopus subject areas
- Chemistry(all)