Benzoyl Peroxide → 3-Bromopyrido[2,3-d]pyridazin-8(7H)-one

Temperature

77 °C

To a solution of methyl 5-bromo-3-methylpicolinate (1.785 g, 7.76 mmol) in 30 mL of CCl4 was added N-bromosuccinimide (4.23 g, 23.8 mmol) and benzoyl peroxide (0.199 g, 0.822 mmol). The reaction was heated at 77° C. for 6 h. The reaction mixture was cooled to RT, filtered through a pad of Celite and washed with CCl4. The filtrate was evaporated in vacuo to give a yellow oil. The oil was dissolved in 40 mL MeOH and anhydrous hydrazine (3.00 ml, 95.6 mmol) was added dropwise at 25° C. Upon complete addition the reaction mixture was heated at 78° C. overnight. The reaction mixture was cooled to RT and the solid was filtered, washed with MeOH and CHCl3 and dried by suction. The filtrate was evaporated onto silica gel and purified flash chromatography eluting with 2M NH3 in MeOH:CHCl3 (0:1→3:47) to give the title compound as a light-yellow amorphous solid. MS m/z: 225.9, 227.9 [M+1].

1. temperatureThe reaction mixture was cooled to RT
2. filtrationfiltered through a pad of Celite
3. washwashed with CCl4
4. customThe filtrate was evaporated in vacuo
5. customto give a yellow oil
6. additionUpon complete addition the reaction mixture
7. temperaturewas heated at 78° C. overnight
8. temperatureThe reaction mixture was cooled to RT
9. filtrationthe solid was filtered
10. washwashed with MeOH and CHCl3
11. customdried by suction
12. customThe filtrate was evaporated onto silica gel
13. custompurified flash chromatography
14. washeluting with 2M NH3 in MeOH:CHCl3 (0:1→3:47)

ORD record

ord-932a1e08d01c4701a7fbbe629a72a8ec

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07759337B2