Hydrochloric Acid → 5-(Propan-2-yl)-1,2-oxazol-3-amine

Temperatur

40 °C

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).

1. temperaturethe reaction warmed to 50° C. for 2.5 h
2. customThe reaction is removed from the oil bath
3. temperatureto cool to rt
4. additionAt this point a solution of NaOH (30% in H2O) is added
5. customto give a solution of pH 11
6. customthe layers separated
7. extractionThe water layer is extracted with EtOAc (3×) until no more product
8. dry with materialThe combined organics are dried (Na2SO4)
9. customevaporated

ORD-Eintrag

ord-eb5f6f9bdefb4aa59ca0bc3b472c02e6

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08541432B2