1,8-Diazabicyclo(5.4.0)undec-7-ene → 2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic Acid Methyl Ester

1,8-Diazabicyclo[5.4.0]undec-7-ene (5 ml) was added to a stirred, chilled, mixture of (3-fluoro-phenyl)-propynoic acid methyl ester (2.67 g) and 1-amino-3-methoxy-pyridazin-1-ium mesitylene sulphonate (4.89 g) in acetonitrile (80 ml) and the mixture was stirred at 0° for 1 hour then at ambient temperature for 18 hours. The mixture was concentrated in vacuo, and partitioned between ethyl acetate (150 ml) and water (150 ml). The aqueous phase was separated and further extracted with ethyl acetate (2×100 ml). The combined organic extracts were washed with water (2×50 ml), brine (25 ml), dried (MgSO4), filtered and evaporated in vacuo to give a solid which was triturated with anhydrous ether: petroleum ether (1:0.5) to give the title compound as a brown solid (2.4 g, 53%).

1. temperaturechilled
2. waitat ambient temperature for 18 hours
3. concentrationThe mixture was concentrated in vacuo
4. custompartitioned between ethyl acetate (150 ml) and water (150 ml)
5. customThe aqueous phase was separated
6. extractionfurther extracted with ethyl acetate (2×100 ml)
7. washThe combined organic extracts were washed with water (2×50 ml), brine (25 ml)
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. customevaporated in vacuo
11. customto give a solid which
12. customwas triturated with anhydrous ether: petroleum ether (1:0.5)

ORD record

ord-bfebd09484c84a589f621039e97214ea

Source dataset

uspto-grants-2005_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06861429B2