Diisobutylaluminum hydride → (5-(3,4-Dichlorophenylamino)pyrazin-2-yl)methanol

Temperature

-78 °C

A suspension of methyl 5-((3,4-dichlorophenyl)amino)pyrazine-2-carboxylate (0.53 g, 1.778 mmol) in THF (18 mL) was cooled at −78° C. and 1M solution of DIBAL-H (5.33 ml, 5.33 mmol) in toluene was added. The mixture was stirred for 1.5 h while warming to room temperature. The reaction mixture was diluted with THF (20 mL) and quenched with Na2SO4.10H2O followed by a few drops of water. The mixture was stirred at room temperature for 18 h, then filtered through a pad of Celite topped with silica gel. The pad was washed with ethyl acetate and the filtrate concentrated. The residue was purified on silica gel using 40-100% ethyl acetate in hexanes. The desired fractions were concentrated to give (5-(3,4-dichlorophenylamino)pyrazin-2-yl)methanol as a yellow solid (0.293 g, 61%). 1H NMR (400 MHz, DMSO-d6) δ ppm 9.80 (1H, s), 8.02-8.34 (3H, m), 7.46-7.66 (2H, m), 5.36 (1H, t, J=5.77 Hz), 4.51 (2H, d, J=5.77 Hz). LCMS: R.T.=3.65; [M+H]+=269.96.

1. temperaturewhile warming to room temperature
2. customquenched with Na2SO4.10H2O
3. stirringThe mixture was stirred at room temperature for 18 h
4. filtrationfiltered through a pad of Celite
5. washThe pad was washed with ethyl acetate
6. concentrationthe filtrate concentrated
7. customThe residue was purified on silica gel using 40-100% ethyl acetate in hexanes
8. concentrationThe desired fractions were concentrated

ORD record

ord-0446b5c9c8254e05aa62f1f81109fcc4

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08841301B2