1-Methylpiperazine → 3-Chloro-6-(4-methylpiperazin-1-yl)pyridazine

Temperature

100 °C

A 25-mL single-neck round bottomed flask equipped with a magnetic stirrer was purged with nitrogen and charged with 3,6-dichloropyridazine (1.49 g, 10.0 mmol) and N-methylpiperazine (1.17 g, 11.7 mmol), and the flask was placed in an oil bath, which was heated to 100° C. After 1.5 h the flask was cooled to room temperature, and the resulting cake was crushed and triturated with acetonitrile (10 mL). The suspension was filtered, and the filter cake was mixed with 10% aqueous potassium carbonate (15 mL). The resulting mixture was extracted with MtBE (2×35 mL). The organic extracts were combined, dried over sodium sulfate and filtered. The filtrate was evaporated under reduced pressure to afford a 60% yield (1.27 g) of 122e as a white solid: mp 106-107° C.; 1H NMR (300 MHz, CDCl3) δ 7.20 (d, 1H, J=9.5 Hz), 6.89 (d, 1H, J=9.6 Hz), 3.65 (t, 4H, J=5.1 Hz), 2.53 (t, 4H, J=5.1 Hz), 2.35 (s, 3H); MS (ESI+) m/z 213.1 (M+H).

1. customA 25-mL single-neck round bottomed flask equipped with a magnetic stirrer
2. customwas purged with nitrogen
3. customthe flask was placed in an oil bath
4. temperatureAfter 1.5 h the flask was cooled to room temperature
5. customthe resulting cake was crushed
6. customtriturated with acetonitrile (10 mL)
7. filtrationThe suspension was filtered
8. additionthe filter cake was mixed with 10% aqueous potassium carbonate (15 mL)
9. extractionThe resulting mixture was extracted with MtBE (2×35 mL)
10. dry with materialdried over sodium sulfate
11. filtrationfiltered
12. customThe filtrate was evaporated under reduced pressure

ORD record

ord-152fd8300ac14e2f8b760596ae79496d

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09249123B2