Reaction #49693

Reaction equation

(+)-8-chloro-6,11-dihydro-11-(4-piperazinyl)-5H-benzo[5,6]cyclohepta-[1,2-b]pyridine

4-pyridylcarbinol N-oxide

carbon tetrabromide

triethylamine

triphenylphosphine

→

(+)-8-chloro-6,11-dihydro-11-[4-(4-pyridinylmethyl)-1-piperazinyl]-5h-benzo[5,6]cyclohepta-[1,2-b]pyridine

Yield 75.5%

Solvents

methylene chloride

methylene chloride

Conditions

Workup

1. 1
   Washwashed once with 0.5M aqueous sodium bicarbonate
2. 2
   DryingThe organic portion was dried over sodium sulfate
3. 3
   Filtrationfiltered
4. 4
   Concentrationconcentrated in vacuo
5. 5
   OtherThe residue was purified via flash chromatography (5% methanol saturated with ammonia in methylene chloride)

Procedure

To a mixture of 213 mg (1.70 mmol) of 4-pyridylcarbinol N-oxide and 563 mg (1.70 mmol) of carbon tetrabromide in 14 mL of dry methylene chloride at room temperature and under an argon atmosphere was added in one portion 446 mg (1.70 mmol) of triphenylphosphine. After 45 minutes, 313 mg (0.997 mmol) of (+)-8-chloro-6,11-dihydro-11-(4-piperazinyl)-5H-benzo[5,6]cyclohepta-[1,2-b]pyridine was added followed by 237 mL (1.78 mmol) of triethylamine. The reaction mixture was then allowed to stir at room temperature overnight, after which it was taken up in methylene chloride and washed once with 0.5M aqueous sodium bicarbonate and then brine. The organic portion was dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified via flash chromatography (5% methanol saturated with ammonia in methylene chloride) to provide 305 mg of (+)-8-chloro-6,11-dihydro-11-[4-(4-pyridinylmethyl)-1-piperazinyl]-5h-benzo[5,6]cyclohepta-[1,2-b]pyridine, N-oxide as a glass: MS (CI) m/z 421 (M+ +1);

Source