Pyridine → HCID 22169697, compound

4,5-Bis(4-chlorophenyl)pyridazin-3(2H)-one (16.5 g, 52.2 mmol) was suspended in toluene (50 mL). To the resultant solution was added pyridine (8.3 mL, 104.4 mmol), followed by the addition of POCl3 (14.3 mL, 156.6 mmol). The reaction mixture was placed in an oil bath preheated at 110° C. After 4 h, the reaction mixture was cooled to RT, then poured over 500 g ice to quench the excess POCl3. The dark mixture was extracted with EtOAc (2×300 mL). The combined organic layers were washed with water (500 mL), and filtered through a silica gel pad (˜50 g). The filtrate was concentrated under reduced pressure to give the title compound, 3-chloro-4,5-bis(4-chlorophenyl)pyridazine as a pale colored solid (16.0 g, 92%). MS: M+H=335. 1H NMR (CDCl3, 500 MHz): δ 9.24(1H, s), 7.35 (2H, d, J=10 Hz), 7.26 (2H, d, J=10.0 Hz), 7.08–7.16 (4H, m).

1. customThe reaction mixture was placed in an oil bath
2. custompreheated at 110° C
3. customto quench the excess POCl3
4. extractionThe dark mixture was extracted with EtOAc (2×300 mL)
5. washThe combined organic layers were washed with water (500 mL)
6. filtrationfiltered through a silica gel pad (˜50 g)
7. concentrationThe filtrate was concentrated under reduced pressure

ORD record

ord-07a66ff5aefc43b88808acad0a8e6c4f

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07037910B2