1-Methylpiperazine → HCID 90411760, compound

3,4,5-Trichloropyridazine (3 g, 16.36 mmol) was dissolved in dry NMP (18 mL) and cooled in an ice-bath. DIPEA (2.326 g, 3.135 mL, 18 mmol) was added, followed, dropwise, by 1-methylpiperazine (1.721 g, 1.906 mL, 17.18 mmol). The resulting mixture was stirred at RT overnight. The reaction mixture was concentrated under reduced pressure to give an brown solid which was partitioned between 10% MeOH in DCM and saturated NaHCO3. The aqueous layer was extracted with further 10% MeOH in DCM (5×20 mL) and the combined organics were dried over Na2SO4, filtered and concentrated under reduced pressure to give a brown oil which was purified by column chromatography (7.5% MeOH in DCM, ˜300 mL silica, loaded in DCM) to provide 3,4-dichloro-5-(4-methylpiperazin-1-yl)pyridazine as a light yellow solid (2.36 g, 58% Yield).

1. temperaturecooled in an ice-bath
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. customto give an brown solid which
4. customwas partitioned between 10% MeOH in DCM and saturated NaHCO3
5. extractionThe aqueous layer was extracted with further 10% MeOH in DCM (5×20 mL)
6. dry with materialthe combined organics were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customto give a brown oil which
10. customwas purified by column chromatography (7.5% MeOH in DCM, ˜300 mL silica, loaded in DCM)

ORD record

ord-6f61b87eaf494ae68df575b721bd09fa

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08957078B2