m-Chloroperbenzoic acid → 5-Bromo-2-chloro-1-oxo-1lambda~5~-pyridine

Temperatur

60 °C

To a solution of 5-bromo-2-chloropyridine (1.0 eq.) in chloroform (0.38 M) was added 77% meta-chloroperbenzoic acid (mCPBA) (4.0 eq.) and heated at 60° C. for 20 hours. After cooling to room temperature, Ca(OH)2 (5.3 eq.) was added, and the resulting precipitate was stirred for 30 minutes. The precipitate was filtered and washed with 3:1 CHCl3/methanol. The filtrate was concentrated en vacuo to give a solid, which was stirred in 30% ethyl acetate in hexane and filtered to give the desired N-oxide. The filtrate was concentrated en vacuo, and the residue was purified by a COMBIFLASH® system (ISCO) using 0-100% ethyl acetate in hexane to give more of the desired N-oxide. The two batches were combined and carried onto the next step.

1. temperatureAfter cooling to room temperature
2. filtrationThe precipitate was filtered
3. washwashed with 3:1 CHCl3/methanol
4. concentrationThe filtrate was concentrated en vacuo
5. customto give a solid, which
6. filtrationfiltered

ORD-Eintrag

ord-a8efac9a566943d9948b864a5f45725c

Quelldatensatz

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08466167B2