Aluminum(III) Chloride → HCID 22169698, compound

The crude 2-benzyl-4,5-bis(4-chlorophenyl)pyridazin-3(2H)-one from the above reaction was dissolved in toluene (350 mL). Aluminum chloride (AlCl3, 46.3 g, 348.0 mmol) was then added to the toluene solution, producing an exotherm. The reaction was then placed in an oil bath preheated at 75° C. for 3 h. After this time, the reaction mixture was poured into ice-water (1000 mL), and the resulting mixture was extracted with EtOAc (3×500 mL). The combined organic layers were washed with water (500 mL), then filtered through a silica gel pad (˜50 g) to remove residual alumina salts. The organic solvents were evaporated under reduced pressure to nearly dryness. Diethyl ether (Et2O, 500 mL) was added with stirring. After stirring for 15 min at RT, hexane (1000 mL) was added subsequently. The resultant beige colored solid was collected by filtration and subsequently washed with a hexane-ether mixture (8:2). The title compound, 4,5-bis(4-chlorophenyl)pyridazin-3(2H)-one, (33.0 g, 92%) was obtained as a solid. MS: M+H=317. 1H NMR (CDCl3, 500 MHz): δ 11.94 (1H, br), 7.89 (1H, s), 7.23-7.32 (4H, m), 7.18 (2H, d, J=10.0 Hz), 7.07 (2H, d, J=10 Hz).

1. customproducing an exotherm
2. customThe reaction was then placed in an oil bath
3. extractionthe resulting mixture was extracted with EtOAc (3×500 mL)
4. washThe combined organic layers were washed with water (500 mL)
5. filtrationfiltered through a silica gel pad (˜50 g)
6. customto remove residual alumina salts
7. customThe organic solvents were evaporated under reduced pressure to nearly dryness
8. additionDiethyl ether (Et2O, 500 mL) was added
9. stirringAfter stirring for 15 min at RT
10. additionhexane (1000 mL) was added subsequently
11. filtrationThe resultant beige colored solid was collected by filtration
12. washsubsequently washed with a hexane-ether mixture (8:2)

ORD record

ord-2dcbc7b8245e4f018f9ed33ab363ecfb

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07378418B2