Hydroxylamine → 5-(1H-imidazol-4-yl)isoxazole

A mixture of (E)-3-(dimethylamino)-1-(1-trityl-1H-imidazol-4-yl)prop-2-en-1-one (54.0 g, 133 mmol) and HONH2*HCl (10.13 g, 146 mmol) in MeOH (800 mL) was heated to reflux for 18 h. The mixture was then allowed to cool to RT and was concentrated in vacuo. The residue obtained was taken up in DCM and washed with H2O. The org. phase was then dried over Na2SO4, filtered and concentrated in vacuo. The residue obtained was stirred in Et2O, and the suspension was filtered. The filter cake was dried in vacuo at 40° C. The aqueous phase was then concentrated in vacuo and the residue obtained was placed in a Soxlet apparatus and continuously extracted with DCM for 36 h. The organic phase was then concentrated in vacuo and the residue obtained was stirred in DCM. The suspension was then filtered and the filter cake was dried in vacuo at 40° C. The two filter cakes were then crystallized in AcOEt to give the title compound (5.44 g). UPLC-MS: MS 136.1 (M+H+); UPLC rt 0.33 min.

1. temperaturewas heated
2. temperatureto reflux for 18 h
3. concentrationwas concentrated in vacuo
4. customThe residue obtained
5. washwashed with H2O
6. dry with materialphase was then dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe residue obtained
10. filtrationthe suspension was filtered
11. customThe filter cake was dried in vacuo at 40° C
12. concentrationThe aqueous phase was then concentrated in vacuo
13. customthe residue obtained
14. extractioncontinuously extracted with DCM for 36 h
15. concentrationThe organic phase was then concentrated in vacuo
16. customthe residue obtained
17. filtrationThe suspension was then filtered
18. customthe filter cake was dried in vacuo at 40° C
19. filtrationThe two filter cakes
20. customwere then crystallized in AcOEt

ORD record

ord-c8b91b7d7fe44783bd3bfb5386602239

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08853203B2