Hydrogen Bromide → Imidazo(1,2-b)pyridazine, 6-chloro-

Temperature

110 °C

Hydrobromic acid (48% solution in water, 1.8 mL, 15.47 mmol) was added to a solution of 2-bromo-1,1-diethoxyethane (11.6 mL, 77.11 mmol) in water (18 mL) at ambient temperature and the resulting mixture was heated at 110° C. After 45 minutes, the reaction mixture was cooled and diethyl ether was added. The organic layer was separated, dried over magnesium sulphate and the solvent evaporated to obtain a colorless oil, which was added to a suspension at 0° C. of 6-chloropyridazin-3-amine (5.0 g, 38.60 mmol) in n-butanol (8 mL). The resulting mixture was heated at 130° C. overnight. The solvent was removed under reduced pressure, the residue was taken up in a mixture of ethyl acetate and water and the organic layer was separated. The aqueous layer was treated with solid sodium hydrogencarbonate until a basic pH was reached and extracted several times with ethyl acetate. The organic layers were combined, dried over magnesium sulphate and the solvent removed under reduced pressure. The resulting residue was treated with diisopropyl ether, filtered and dried in vacuo to yield the title compound (4.8 g, 85%) as a beige solid.

1. temperaturethe reaction mixture was cooled
2. customThe organic layer was separated
3. dry with materialdried over magnesium sulphate
4. customthe solvent evaporated
5. customto obtain a colorless oil, which
6. temperatureThe resulting mixture was heated at 130° C. overnight
7. customThe solvent was removed under reduced pressure
8. additionthe residue was taken up in a mixture of ethyl acetate and water
9. customthe organic layer was separated
10. additionThe aqueous layer was treated with solid sodium hydrogencarbonate until a basic pH
11. extractionextracted several times with ethyl acetate
12. dry with materialdried over magnesium sulphate
13. customthe solvent removed under reduced pressure
14. additionThe resulting residue was treated with diisopropyl ether
15. filtrationfiltered
16. customdried in vacuo

ORD record

ord-7e96aa7062514f35b4ad3d6cec794120

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09133200B2