Reaction #42660

Reaction equation

sodium bicarbonate

Phosgene

2-oxo-1-piperidinium-4-yl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-4-ium dichloride

2,6-lutidine

→

title compound

Yield 49.9%

4-(2-Oxo-2,3-dihydro-1H-imidazo[4,5]pyridin-1-yl)piperidine-1-carbonyl chloride

Yield 49.9%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Extractionextracted with ethyl acetate
2. 2
   WashThe organic layer was washed with water (2×), saturated brine
3. 3
   Dryingdried over magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Concentrationconcentrated
6. 6
   workup.ADDITIONDichloromethane (10 mL) was added
7. 7
   Filtrationthe mixture was filtered

Procedure

Phosgene (20% wt. in toluene; 1.8 mL, 3.43 mmol) was added to a suspension of 2-oxo-1-piperidinium-4-yl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-4-ium dichloride (100 mg, 0.343 mmol) and 2,6-lutidine (0.50 mL, 4.293 mmol) in dichloromethane (5 mL) at 0° C. After 2 h, the solution was added to saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The organic layer was washed with water (2×), saturated brine, dried over magnesium sulfate, filtered and concentrated. Dichloromethane (10 mL) was added, and the mixture was filtered to give the title compound as a solid (48 mg). MS 281 (M+1). 1H NMR (500 MHz, (CD3)2SO) δ 11.58 (s, 1H), 7.90 (d, J=5.1 Hz, 1H), 7.67 (d, J=7.6 Hz, 1H), 7.01-6.99 (m, 1H), 4.52-4.46 (m, 1H), 4.31-4.23 (m, 2H), 3.38-3.33 (m, 1H), 3.19-3.14 (m, 1H), 2.32-2.24 (m, 2H), 1.84-1.81 (m, 2H).

Source