Dimethylformamide → 8-Chloroimidazo[1,5-a]pyrazine

In an oven dried flask filled with nitrogen was added N-(3-Chloro-pyrazin-2-ylmethyl)-formamide (3.8 g, 0.022 mol) followed by MeCN (60 mL, 1 mol) and the reaction mixture was degassed 3×. POCl3 (10 mL, 0.1 mol) was added to the reaction mixture dropwise and the reaction mixture was stirred at rt for 5 min before DMF (couple of drops) was added in one portion. The reaction mixture was heated at 75° C. overnight under a consistent N2 flow. The excess of POCl3 was removed under reduced pressure and the residue was quenched with 2 N NH3 in i-PrOH at 0° C. with vigorous stirring to adjust the pH to 9. The crude reaction mixture was then charged with water and the aqueous layer was washed with DCM. The combined organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the title compound as a brown solid.

1. customIn an oven dried flask
2. additionfilled with nitrogen
3. customthe reaction mixture was degassed 3×
4. additionwas added in one portion
5. customThe excess of POCl3 was removed under reduced pressure
6. customthe residue was quenched with 2 N NH3 in i-PrOH at 0° C.
7. customThe crude reaction mixture
8. washthe aqueous layer was washed with DCM
9. dry with materialThe combined organic layer was dried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated under reduced pressure

ORD record

ord-923464308e0c4b0694c8bd7cb803cca9

Source dataset

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07648987B2