Ethylene Glycol → tert-Butyl 4-[4-(2-hydroxyethoxy)-1,2,5-thiadiazol-3-yl]-1-piperazinecarboxylate

참여 물질

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반응 단계

K-t-BuO (1.24 g, 11 mmol) was added to a mixture of the product obtained in Step 1 (1.98 g, 6.5 mmol) and ethylene glycol (2.54 ml, 45.5 mmol) in pyridine (15 ml). The reaction mixture was stirred at 100° C. for 6 h and at room temperature overnight. The solution was then poured into ice-water and diluted with EtOAc. The organic phase was dried (MgSO4) and the solvent removed under reduced pressure. The residue was purified by chromatography on silica gel eluting hexane/EtOAc (1:1) to give 1.71 g (65%) of title product as an orange oil. MS m/z 331 (M+H)+. Step 3: tert-Butyl 4-(4-{2-[(2-oxo-2H-chromen-7-yl)oxy]ethoxy}-1,2,5-thiadiazol-3-yl)-1-piperazinecarboxylate.

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