Piperazine → 1-(Thiazol-2-yl)piperazine

2-Bromothiazole (15 g, 91.45 mmol) and piperazine (27.6 g, 320 mmol) were dissolved in 1-butanol (290 ml) and the solution was refluxed for 5 h and stirred at room temperature for 15 h. The precipitate was filtered off, the mother liquor was concentrated and saturated sodium carbonate solution (100 ml) was added to the residue. The mixture was extracted with methylene chloride (2×80 ml) and the organic phases were combined, dried over magnesium sulfate and concentrated in vacuo. The crude product was purified by column chromatography (silica gel) with ethyl acetate/methanol (1:1). Yield: 14.2 g (91%)

1. temperaturethe solution was refluxed for 5 h
2. filtrationThe precipitate was filtered off
3. concentrationthe mother liquor was concentrated
4. additionsaturated sodium carbonate solution (100 ml) was added to the residue
5. extractionThe mixture was extracted with methylene chloride (2×80 ml)
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. customThe crude product was purified by column chromatography (silica gel) with ethyl acetate/methanol (1:1)

ORD record

ord-c1475dfe5ff04c32996036f9a4ed9011

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08119805B2