Methyl iodide → 4-Bromo-6-chloro-2-methyl-2,3-dihydropyridazin-3-one

A 250-mL single-necked round bottomed flask equipped with a magnetic stirrer was purged with nitrogen and charged with 4-bromo-6-chloropyridazin-3(2H)-one (1.00 g, 4.77 mmol) and DMF (15 mL). Sodium hydride (60% by weight in oil, 229 mg, 5.73 mmol) was added in one portion. After stirring at room temperature for 10 minutes, iodomethane (1.02 g, 7.16 mmol) was added and the reaction stirred at room temperature for 1.5 h. The reaction was then quenched with aqueous saturated sodium bicarbonate (10 mL) and the resulting solution poured into water (150 mL). The mixture was then extracted with ethyl acetate (250 mL). The organic layer was dried over sodium sulfate. The drying agent was then removed by filtration, and the filtrate was concentrated under reduced pressure to residue. Purification by column chromatography afforded 103a in a 68% yield (722 mg) as a white solid: mp 107-108° C.; 1H NMR (300 MHz, CDCl3) δ 7.62 (s, 1H), 3.81 (s, 3H).

1. customA 250-mL single-necked round bottomed flask equipped with a magnetic stirrer
2. customwas purged with nitrogen
3. stirringthe reaction stirred at room temperature for 1.5 h
4. customThe reaction was then quenched with aqueous saturated sodium bicarbonate (10 mL)
5. additionthe resulting solution poured into water (150 mL)
6. extractionThe mixture was then extracted with ethyl acetate (250 mL)
7. dry with materialThe organic layer was dried over sodium sulfate
8. customThe drying agent was then removed by filtration
9. concentrationthe filtrate was concentrated under reduced pressure to residue
10. customPurification by column chromatography

ORD record

ord-443326d0502141119ac21ae4e7019855

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08975260B2