Regioselective Amination or Alkoxylation of Halogenated Amino-, Thio- or Alkoxypyridines via Pyridyne Intermediates
Martin, Benjamin, Knochel, Paul, Heinz, Benjamin, Djukanovic, Dimitrije, Siemens, Fiona and Idriess, Mohamed (2021) Regioselective Amination or Alkoxylation of Halogenated Amino-, Thio- or Alkoxypyridines via Pyridyne Intermediates. Synthesis, 53. A-I.
Abstract
The treatment of 3-halopyridines (Cl, Br) bearing an R-substituent in position 2 (R = OEt, NEt2, N-piperidyl, or SEt) or in position 5 (R = OMe, OEt, SEt, NMe2, NEt2, or aryl) with KHMDS and an amine at 25 °C for 12 hours in THF provided regioselectively 3- and 4-aminated pyridines in 56–90% yields. The reaction of 3-bromo-2-diethylaminopyridine with various alcohols in the presence of t-BuOK/18-crown-6 in THF at 80 °C for 20–60 hours gave various 4-alkoxy-2-diethylaminopyridines in 61–81% yields. These substitution reactions were proposed to proceed via pyridyne intermediates.
Item Type: | Article |
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Keywords: | potassium bases, pyridines, amination, alkoxylation, pyridynes |
Date Deposited: | 01 Feb 2022 00:45 |
Last Modified: | 01 Feb 2022 00:45 |
URI: | https://oak.novartis.com/id/eprint/45742 |