Dimethylformamide → 8-CHLOROIMIDAZO[1,5-A]PYRAZINE

To an oven dried flask filled with nitrogen was added N-(3-chloro-pyrazin-2-ylmethyl)-formamide (3.000 g, 0.01748 mol) followed by MeCN (60 mL). POCl3 (4.89 mL, 0.0524 mol) was added to the reaction mixture dropwise at 0° C. and the reaction mixture was stirred at 0° C. for 5 min before DMF (0.2 mL) was added. The mixture was then warmed up to rt and stirred at rt for overnight. The excess of POCl3 was removed under reduced pressure and the residue was quenched with solution of 2N 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 titled compound. 1H NMR (400 MHz, CDCl3) δ 7.38 (d, J=4.80 Hz, 1H) 7.80 (d, J=5.05 Hz, 1H) 7.87 (s, 1H) 8.28 (s, 1H). MS (ES+): m/z 154.13, 156.02 [MH+]; HPLC: tR=2.02 min (OpenLynx, polar—7 min).

1. customTo an oven dried flask
2. additionfilled with nitrogen
3. additionwas added
4. customThe excess of POCl3 was removed under reduced pressure
5. customthe residue was quenched with solution of 2N NH3 in i-PrOH at 0° C.
6. stirringwith vigorous stirring
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-43eebe2beb074cb194368922b83a79d0

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08481733B2