Réaction #486982

Équation de réaction

hydrochloric acid

sodium hydride

1-(hydroxyimino)ethylamine

3,5-bis(methoxycarbonyl)pyridine

→

5-(3-methyl-1,2,4-oxadiazol-5-yl)-3-pyridinecarboxylic acid

Rendement 32.0%

Solvants

water

ethyl acetate

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   Températurerefluxed for 30 minutes
2. 2
   Températurethe mixture was refluxed for 3 hours
3. 3
   TempératureAfter being cooled to room temperature
4. 4
   workup.STIRRINGunder stirring
5. 5
   FiltrationThe resulting precipitate was collected by filtration
6. 6
   Lavagewashed with water
7. 7
   Autredried in vacuo

Mode opératoire

To a suspension of 1-(hydroxyimino)ethylamine (7.4 g) in dry tetrahydrofuran (450 ml) was added sodium hydride (3.7 g, 60% in mineral oil) carefully. The mixture was stirred at room temperature for 15 minutes, and refluxed for 30 minutes. To this mixture was added 3,5-bis(methoxycarbonyl)pyridine (15 g), and the mixture was refluxed for 3 hours. After being cooled to room temperature, the reaction mixture was poured into a mixture of ethyl acetate (200 ml) and water (200 ml) under stirring. The aqueous layer was adjusted to pH 3.5 with 10% hydrochloric acid. The resulting precipitate was collected by filtration, washed with water and dried in vacuo to afford 5-(3-methyl-1,2,4-oxadiazol-5-yl)-3-pyridinecarboxylic acid (5.04 g).

Source