Furfurylamine → Furfurylamine
Reaction equation
N[C:2]1[C:7]([OH:8])=[CH:6][C:5]([Br:9])=[CH:4][N:3]=1.[CH2:10]([NH2:16])[C:11]1[O:15][CH:14]=[CH:13][CH:12]=1>>[Br:9][C:5]1[CH:6]=[C:7]([OH:8])[CH:2]=[N:3][CH:4]=1.[CH2:10]([NH2:16])[C:11]1[O:15][CH:14]=[CH:13][CH:12]=1Participants
Procedure
In another example, 6-bromooxazolo[4,5-b]pyridine, when submitted sequentially to palladium catalyzed coupling to N-methyl-N-(tert-butoxycarbonyl)-4-penten-2-amine and deprotection with trifluoroacetic acid, gives (4E)-N-methyl-5-(6-oxazolo[4,5-b]pyridinyl)-4-penten-2-amine. The requisite 6-bromooxazolo[4,5-b]pyridine can be produced from 2-amino-5-bromo-3-pyridinol by condensation with formic acid or a trialkyl orthoformate, using methodology similar to that of M-C. Viaud et al., Heterocycles 41: 2799-2809 (1995). The use of other carboxylic acids produces 2-substituted-6-bromooxazolo[4,5-b]pyridines, which are also substrates for the Heck reaction. The synthesis of 2-amino-5-bromo-3-pyridinol proceeds from furfurylamine (Aldrich Chemical Company). Thus, 5-bromo-3-pyridinol (produced from furfurylamine according to U.S. Pat. No. 4,192,946) can be chlorinated, using methods described by V. Koch et al., Synthesis, 499 (1990), to give 2-chloro-5-bromo-3-pyridinol, which in turn can be converted to 2-amino-5-bromo-3-pyridinol by treatment with ammonia.
Workup
- customfor the Heck reaction
Sources & evidence
- ORD record
- ord-d5f8cdfe31e440f2a429f87a320b80ed
- Source dataset
- uspto-grants-2002_09
- Patent number
- US06455554B1
Reaction notes
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