[Br:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6](Br)[C:7]=1/[CH:8]=[N:9]/[NH:10][CH2:11][CH2:12][OH:13].[H-].[Na+]>C1COCC1>[Br:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6]2[N:10]([CH2:11][CH2:12][OH:13])[N:9]=[CH:8][C:7]=12In analogy to GP2, 520 mg of 2-{N′-[1-(3,5-Dibromo-pyridin-4-yl)-meth-(E)-ylidene]-hydrazino}-ethanol (Intermediate 1.2, 1.61 mmol, 1 eq) were dissolved in 14 mL dry THF, treated at rt with 155 mg 50-60% sodium hydride (3.54 mmol, 2.2 eq) and subsequently refluxed for 90 min. The reaction mixture was quenched with water, extracted with ethyl acetate, the combined organic layers dried and concentrated in vacuo to yield 424 mg of a crude product, which was optionally further purified by trituration or flash column chromatography.
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