Pyridine → N-(6-chloroimidazo[1,2-b]pyridazin-2-yl)acetamide

HRID 1162427Notes

Reaction equation

[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[C:9]([NH2:11])[N:10]=2)[N:7]=1.[C:12](OC(=O)C)(=[O:14])[CH3:13].N1C=CC=CC=1>CN(C)C1C=CN=CC=1.C(Cl)Cl>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[C:9]([NH:11][C:12](=[O:14])[CH3:13])[N:10]=2)[N:7]=1

Participants

Conditions

Temperature: 25 °C

Procedure

To a 250-mL, round-bottomed flask was added 6-chloroimidazo[1,2-b]pyridazin-2-amine from Step 3 (0.67 g, 4.0 mmol), CH2Cl2 (60 mL), acetic anhydride (0.45 mL, 4.8 mmol), pyridine (0.49 mL, 6.0 mmol), and 4-(dimethylamino)pyridine (4.9 mg, 0.040 mmol). The mixture was stirred at 25° C. for 24 h. The reaction mixture was concentrated and then diluted with aq. NaHCO3 and extracted with 25% iPrOH/CHCl3 (3×100 mL). The combined extracts were washed with brine (100 mL), dried (Na2SO4) and concentrated onto silica. Purification by silica gel chromatography (0 to 4% MeOH (2 M in NH3)/CH2Cl2) afforded the title compound as a yellow solid (0.62 g, 74%). MS (ESI positive ion) m/z: 211 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 2.10 (s, 3H), 7.33 (d, J=9.4 Hz, 1H), 8.06 (d, J=9.4 Hz, 1H), 8.26 (s, 1H), 10.95 (s, 1H).

Workup

concentrationThe reaction mixture was concentrated
additiondiluted with aq. NaHCO3
extractionextracted with 25% iPrOH/CHCl3 (3×100 mL)
washThe combined extracts were washed with brine (100 mL)
dry with materialdried (Na2SO4)
concentrationconcentrated onto silica
customPurification by silica gel chromatography (0 to 4% MeOH (2 M in NH3)/CH2Cl2)

Sources & evidence

ORD record: ord-5658780de1344548a2ff6e05a77f4425
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07820665B2

Reaction notes

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