Piperazine → 1-(3-Chloropyridin-2-yl)piperazine

Temperature

110 °C

Piperazine (15 g, 174 mmol) was dissolved in dimethyl sulphoxide (309 g) and to this was added 2,3-dichloropyridine (23.4 g, 158 mmol). The reaction mixture was stirred for 60 h at 110° C. Portions of saturated aqueous sodium hydrogencarbonate solution (overall 250 ml) were added to the reaction mixture and the precipitate produced was drawn off. The filtrate was extracted several times with ethyl acetate (150 ml each time) and the cleaned organic phase was dried and the solvent was removed under vacuum. The residue was distilled at 2×10−1 mbar. The product was obtained at an overhead temperature of 95° C. and a bottom temperature of 155° C. Yield: 9.6 g (28% of the theoretical amount).

1. customthe precipitate produced
2. extractionThe filtrate was extracted several times with ethyl acetate (150 ml each time)
3. customthe cleaned organic phase was dried
4. customthe solvent was removed under vacuum
5. distillationThe residue was distilled at 2×10−1 mbar
6. customThe product was obtained at an overhead temperature of 95° C.
7. customa bottom temperature of 155° C

ORD record

ord-c2887a23121144aca6cbc8b14c559091

Source dataset

uspto-grants-2011_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07994167B2