Hydrogen Bromide → 5-Chloroimidazo[1,2-A]pyrazine

NaHCO3 (4.215 g, 50.1736 mmol) and IPA (40 mL) were added to a mixture of 2-bromo-1,1-dimethoxy-ethane (6.37 mL, 10.8066 mmol), 40% HBr (475 mL, 2.3157 mmol) and 2 drops of water previously refluxed for 1 hr. The reaction mixture was stirred for 5 mins and filtered. To the filtrate was added 6-chloro-pyrazin-2-ylamine (1 g, 7.7190 mmol) and the resulting mixture was refluxed for overnight. The reaction was monitored by TLC (50% ethylacetate in hexane). The reaction mixture was neutralized with Na2CO3 and partitioned between ethylacetate and water. The organic layer was washed with water, brine, dried over Na2SO4 and concentrated. Purification by column chromatography on silica gel (1-2% MeOH in CHCl3) afforded 300 mg of the product (25.31% yield).

1. temperaturepreviously refluxed for 1 hr
2. filtrationfiltered
3. temperaturethe resulting mixture was refluxed for overnight
4. custompartitioned between ethylacetate and water
5. washThe organic layer was washed with water, brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated
8. customPurification by column chromatography on silica gel (1-2% MeOH in CHCl3)

ORD record

ord-fe65c3a1d8c0408b94f2bf59208ad84f

Source dataset

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

USRE045173E1