Oxalyl chloride → Methyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate

A 50 mL flask equipped with a reflux condenser and a nitrogen line was charged with 7-bromoimidazo[1,2-a]pyridine-3-carboxylic acid (1.00 g, 4.15 mmol), DCM (20 mL), oxalyl chloride (0.72 mL, 1.46 mmol), and chilled in a ice-water bath. Four drops of DMF were added to the reaction, and the flask was stirred at ambient temperature overnight. The reaction mixture was concentrated to dryness, chilled in an ice water bath, and 30 mL MeOH were added under a nitrogen atmosphere. The reaction mixture was stirred at ambient temperature overnight, concentrated to dryness, and re-suspended in saturated, aqueous sodium bicarbonate solution. The suspension was extracted with DCM and EtOAc, the combined organic extracts were dried over anhydrous sodium sulfate, and concentrated to afford the desired product (0.918 g) as a tan solid.

1. customA 50 mL flask equipped with a reflux condenser
2. temperaturechilled in a ice-water bath
3. concentrationThe reaction mixture was concentrated to dryness
4. temperaturechilled in an ice water bath
5. addition30 mL MeOH were added under a nitrogen atmosphere
6. stirringThe reaction mixture was stirred at ambient temperature overnight
7. concentrationconcentrated to dryness
8. extractionThe suspension was extracted with DCM and EtOAc
9. dry with materialthe combined organic extracts were dried over anhydrous sodium sulfate
10. concentrationconcentrated

ORD record

ord-bd517c00975c420dbe83ec414d99d3e6

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09174981B2