Toluene → 5-(Pyridazin-3-yl)pyridin-2-amine

Temperature

90 °C

To a sealed flask were added 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-amine 145-1 (1.54 g, 7 mmol), 3-chloropyridazine 145-2 (0.8 g, 7 mmol), Pd(PPh3)4 (500 mg, 0.7 mmol), toluene (50 mL), ethanol (12 mL) and 2M Na2CO3 (11 mL). The reaction mixture was bubbled with nitrogen for 2 minutes and stirred at 90° C. for 10 hours. After cooled to room temperature, the solvents were evaporated and the residue was redissolved in dichloromethane (200 ml) and treated with 1M HCl aqueous solution (50 mL). The two layers were separated and the aqueous layer was treated with 10% NaOH aqueous solution to adjust the pH to around 13. The resulting solution was evaporated and the remaining solid was exacted with ethyl acetate (100 mL×3). The combined organic phases were concentrated to give 5-(pyridazin-3-yl)pyridin-2-amine 145-3 as dark brown solid. MS m/z 173.1 (M+1).

1. customThe reaction mixture was bubbled with nitrogen for 2 minutes
2. temperatureAfter cooled to room temperature
3. customthe solvents were evaporated
4. dissolutionthe residue was redissolved in dichloromethane (200 ml)
5. additiontreated with 1M HCl aqueous solution (50 mL)
6. customThe two layers were separated
7. additionthe aqueous layer was treated with 10% NaOH aqueous solution
8. customThe resulting solution was evaporated
9. concentrationThe combined organic phases were concentrated

ORD record

ord-f5ff88721fb74402b3cb457ec478c0c4

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08546396B2