Pyridine → N-(6-bromoimidazo[1,2-a]pyridin-2-yl)acetamide

HRID 1162463Notes

Reaction equation

[CH:1]1[C:9]([Br:10])=[CH:8][N:7]2[C:3](=[N:4][CH:5]=[CH:6]2)[CH:2]=1.C[O:12][C:13]1[C:18]2C=CNC=2N=C(N)[N:14]=1.N1C=CC=CC=1.CC(OCC1C2C(=CC=CC=2)C(COC(C)=O)=C2C=1C=CC=C2)=O>CN(C1C=CN=CC=1)C.C(Cl)Cl>[Br:10][C:9]1[CH:1]=[CH:2][C:3]2[N:7]([CH:6]=[C:5]([NH:14][C:13](=[O:12])[CH3:18])[N:4]=2)[CH:8]=1

Participants

Conditions

Temperature: 35 °C

Procedure

To a 100 mL round-bottomed flask was added 6-bromoH-imidazo[1,2-a]pyridin-2-amine (0.771 g, 3.6 mmol), DCM (30 mL), pyridine (0.44 mL, 5.5 mmol), acetic anhyride (0.41 mL, 4.4 mmol) and DMAP (0.0022 g, 0.018 mmol). The mixture was stirred at 35° C. for 3 h. After cooling to rt, the mixture was concentrated and then taken up in water (100 mL) and extracted with 25% iPrOH/CHCl3 (3×75 mL). The combined extracts were washed with brine (75 mL), dried (Na2SO4) and concentrated in vacuo. The residue was dissolved in MeOH (2 M in NH3)/CH2Cl2 and concentrated onto silica. Purification by silica gel chromatography MeOH (2 M in NH3)/CH2Cl2) afforded the title compound as an orange solid (0.452 g, 49%). MS (ESI, positive ion) m/z: 254 (M(79Br)+1).

Workup

temperatureAfter cooling to rt
concentrationthe mixture was concentrated
extractionextracted with 25% iPrOH/CHCl3 (3×75 mL)
washThe combined extracts were washed with brine (75 mL)
dry with materialdried (Na2SO4)
concentrationconcentrated in vacuo
dissolutionThe residue was dissolved in MeOH (2 M in NH3)/CH2Cl2
concentrationconcentrated onto silica
customPurification by silica gel chromatography MeOH (2 M in NH3)/CH2Cl2)

Sources & evidence

ORD record: ord-f418fecc6914499298004d93adc1597d
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07820665B2

Reaction notes

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