Reaktion #469085

Reaktionsgleichung

2-(4-fluorophenyl)-4-methyl-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone

carbon tetrachloride

N-bromosuccinimide

→

product

Ausbeute 74.0%

2-(4-Fluorophenyl)-4-bromomethyl-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone

Ausbeute 74.0%

Lösungsmittel

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITthe reaction checked after another 1 hour
2. 2
   workup.WAITAfter 30 minutes
3. 3
   WaschenThe acetate solution was washed with saturated NaHCO3, water, and brine
4. 4
   TrocknenThe solution was dried over MgSO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated in vacuo
7. 7
   SonstigeThe residue was chromatographed (flash silica gel, ethyl acetate/hexanes gradient 1:1 to 4:1)

Vorschrift

To a heterogeneous, refluxing solution of 2-(4-fluorophenyl)-4-methyl-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone (590 mg, 1.65 mmol) and carbon tetrachloride (24 mL) was quickly added N-bromosuccinimide (yield: 308 mg, 1.73 mmol) followed by benzoyl peroxide (12 mg, 0.05 mmol). After 1 hour the reaction had only run to near 50% completion. Additional benzoyl peroxide (12 mg, 0.05 mmol) was added, and the reaction checked after another 1 hour. The reaction was still not complete, and so more benzoyl peroxide (4 mg, 0.017 mmol) was added. After 30 minutes, the reaction was completed. The mixture was cooled to 23° C. and diluted with ethyl acetate. The acetate solution was washed with saturated NaHCO3, water, and brine. The solution was dried over MgSO4, filtered, and concentrated in vacuo. The residue was chromatographed (flash silica gel, ethyl acetate/hexanes gradient 1:1 to 4:1) to provide the product (yield: 530 mg, 74%). 1H NMR (300 MHz, CDCl3) δ 3.16 (s, 3H), 4.34 (s, 2H), 7.20 (dd, J=8.8, 8.8 Hz, 2H), 7.67-7.74 (m, 2H), 7.82 (d, J=8.7 Hz, 2H), 7.86 (s, 1H), 8.17 (d, J=8.7 Hz, 2H), MS (APCI+) m/z 437 (M+H)+.

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