Hydrochloric Acid → 6-Bromo-2-methylimidazo[1,2-a]pyridine-3-carboxylic acid

Temperature

80 °C

To a solution of 2-amino-5-bromopyridine (25.0 g, 144.5 mmol) in EtOH (150 mL), was added methyl 2-chloro-3-acetoacetate (18.6 mL, 144.5 mmol), and the mixture was refluxed at 80° C. for 12 h. Then the reaction mixture was allowed to cool to rt, and then were added 8N aqueous sodium hydroxide solution (60 mL, 480 mmol) and water (30 mL). The mixture was stirred at 80° C. for 12 h, allowed to cool to 0° C., and then neutralized by the addition of 6N hydrochloric acid (300 mL). The resulting precipitate was collected by filtration and sequentially washed with water, EtOH and diethyl ether to give the title compound (11.1 g, 30%) as a brown solid.

1. temperatureto cool to rt
2. temperatureto cool to 0° C.
3. filtrationThe resulting precipitate was collected by filtration
4. washsequentially washed with water, EtOH and diethyl ether

ORD record

ord-29d7b98c9ef14744b81d97b17c9e7f2d

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09139589B2