3,6-Dichloropyridazine → tert-Butyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate

Temperature

100 °C

In a microwave vial were mixed: 1,1-dimethylethyl 1-piperazinecarboxylate (135 mg, 0.725 mmol, available from Fluke), 3,6-dichloropyridazine (90 mg, 0.604 mmol, available from Alfa Aesar) and DIPEA (0.137 mL, 0.785 mmol) in Tert-Butanol (2 mL). The reaction was stirred and heated in an Emrys Optimizer microwave at 100° C. for 20 mins then for 30 mins at 150° C. The reaction mixture was partitioned between EtOAc (20 mL) and water (20 mL) and the organic layer washed with brine (20 mL) before being dried through an hydrophobic frit and concentrated. The residue was dissolved in DCM and purified by SP4 on a 12+M silica cartridge using a gradient of 10-50% EtOAc in cyclohexane. The appropriate fractions were collected and concentrated to yield the desired product as a white solid, 1,1-dimethylethyl 4-(6-chloro-3-pyridazinyl)-1-piperazinecarboxylate (114.2 mg). LCMS (Method C): Rt=0.85, MH+=299

1. additionIn a microwave vial were mixed
2. customThe reaction mixture was partitioned between EtOAc (20 mL) and water (20 mL)
3. washthe organic layer washed with brine (20 mL)
4. custombefore being dried through an hydrophobic frit
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in DCM
7. custompurified by SP4 on a 12+M silica cartridge
8. customThe appropriate fractions were collected
9. concentrationconcentrated

ORD record

ord-ca921444a6864b6094abd2188996615d

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08697725B2