Pyridine → 2-Chloro-3-hydrazinopyrazine

Temperature

60 °C

A mixture of 2,3-dichloropyrazine (6.26 g, 42.0 mmol) and anhydrous hydrazine (5 mL, 159 mmol) in pyridine (22 mL, 272 mmol) was stirred at 60° C. for 2.5 h. After cooling to room temperature, the reaction mixture was concentrated in vacuo. The obtained residue was triturated with water. The resulting slurry was filtered, and the collected solid air dried to yield the first crop of the title compound (3.88 g) as a white solid. The filtrate was concentrated in vacuo, the obtained residue was treated by repeating above process to afford additional amount of the product (1.73 g). (total 5.61 g, 92% yield). HPLC/MS (Method C): retention time=0.30 min, [M+H]+=144.8. 1H NMR (500 MHz, DMSO-d6): δ 8.27 (s, 1H), 8.05 (s, 1H), 7.56 (s, 1H), 4.32 (s, 2H); 13C NMR (500 MHz, DMSO-d6) δ 152.62, 140.67, 132.60, 130.01.

1. temperatureAfter cooling to room temperature
2. concentrationthe reaction mixture was concentrated in vacuo
3. customThe obtained residue was triturated with water
4. filtrationThe resulting slurry was filtered
5. customthe collected solid air dried

ORD record

ord-e6c2658d46024dc78325358958c62eb8

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08324241B2