N-bromobutanimide → HCID 118046383, compound

A solution of 5-cyclopropylpyrazin-2-amine (79 mg, 0.584 mmol) in acetonitrile (10 mL) was cooled down to 0° C., and treated with gradual addition of NBS (140 mg, 1.46 mmol) over the course of 1 hour while closely monitoring reaction progress by LCMS. The reaction mixture was concentrated and the residue was triturated with EtOAc (2×5 mL) and the EtOAc supernatants were separated via centrifugation, combined and washed with 1N NaOH (3×1 mL) and the EtOAc layer was dried (over Na2SO4), concentrated and a crude brown reside was obtained. The crude product was further purified by flash chromatography on silica gel eluted with gradient EtOAc/CH2Cl2 (0-30%) to afford 3-bromo-5-cyclopropylpyrazin-2-amine in colorless solid (38.2 mg, 38.5% yield). LCMS (m/z): 214.0/216.0 (MH+), 0.64 min.

1. customreaction progress by LCMS
2. concentrationThe reaction mixture was concentrated
3. customthe residue was triturated with EtOAc (2×5 mL)
4. customthe EtOAc supernatants were separated via centrifugation
5. washwashed with 1N NaOH (3×1 mL)
6. dry with materialthe EtOAc layer was dried (over Na2SO4)
7. concentrationconcentrated
8. customa crude brown reside was obtained
9. customThe crude product was further purified by flash chromatography on silica gel
10. washeluted with gradient EtOAc/CH2Cl2 (0-30%)

ORD record

ord-fdf5dfcf2cc8411d85430461fef1e408

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09242996B2