Reaktion #73337

Reaktionsgleichung

hydroxylamine sulfate

NaOH

NaOH

HCl

4-methyl-3-oxopentanenitrile

→

5-isopropyl-isoxazol-3-ylamine

Lösungsmittel

EtOAc

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe reaction warmed to 50° C. for 2.5 h
2. 2
   SonstigeThe reaction is removed from the oil bath
3. 3
   Temperaturto cool to rt
4. 4
   workup.ADDITIONAt this point a solution of NaOH (30% in H2O) is added
5. 5
   Sonstigeto give a solution of pH 11
6. 6
   Sonstigethe layers separated
7. 7
   ExtraktionThe water layer is extracted with EtOAc (3×) until no more product
8. 8
   TrocknenThe combined organics are dried (Na2SO4)
9. 9
   Sonstigeevaporated

Vorschrift

To a mixture of 4-methyl-3-oxopentanenitrile (11 g, 99 mmol) and water (200 mL) is added NaOH (4.95 g, 124 mmol). Once the NaOH pellets are completely dissolved, hydroxylamine sulfate (8.93 g, 109 mmol) is added and after 5 min the pH is measured (pH 7-8). The reaction is warmed to 40° C. and stirred for 72 h. At this point HCl (13.0 mL, 158 mmol, 37%) is added in one portion and the reaction warmed to 50° C. for 2.5 h. The reaction is removed from the oil bath and allowed to cool to rt. At this point a solution of NaOH (30% in H2O) is added to give a solution of pH 11. EtOAc is then added and the layers separated. The water layer is extracted with EtOAc (3×) until no more product appears in the LCMS of the water layer. The combined organics are dried (Na2SO4) and evaporated to give 5-isopropyl-isoxazol-3-ylamine. MS (ESI) m/z 127.2 (M+1).

Quelle