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

Participants

Reaction Steps

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).

Provenance & Evidence