Reaction #336851

Reaction equation

2-phenyl-2,5-dihydro-pyrazolo-(4,3-C)quinolin-3-one

2-Phenyl-2,5-dihydro-pyrazolo-(4,3-c) quinolin-3-one

N,N-diisopropylethylamine

triphosgene

N,N-diisopropylethylamine

4-methylpiperidine

→

5-(4-Methylpiperidine-1-carbonyl)-2-phenyl-2,5-dihydro-pyrazolo-(4,3-c)quinolin-3-one

Solvents

methylene chloride

Conditions

Workup

1. 1
   OtherThe reaction was quenched by addition of aqueous sodium bicarbonate solution
2. 2
   OtherThe organic layer was collected
3. 3
   Washwashed with brine solution
4. 4
   Dryingdried over sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated in vacuo
7. 7
   OtherThe product was obtained by column chromatography

Procedure

A solution of 2-phenyl-2,5-dihydro-pyrazolo-(4,3-C)quinolin-3-one (4a) (0.261 g, 1 mM) in 2 mL of anhydrous methylene chloride was stirred with N,N-diisopropylethylamine (0.145 g, 1.2 mM) and triphosgene (0.173 g, 0.55 mM) at 0° C. for 1 hour and 25° C. for 2 hours. N,N-diisopropylethylamine (0.145 g, 1.2 mM) and 4-methylpiperidine (0.208 g, 2 mM) were added at 0° C. and the reaction mixture was stirred overnight at room temperature. The reaction was quenched by addition of aqueous sodium bicarbonate solution. The organic layer was collected, washed with brine solution, dried over sodium sulfate, filtered and concentrated in vacuo. The product was obtained by column chromatography. 1H NMR (CDCl3) δ (ppm): 1.0 (3H, d, J=6.59), 1.6 (4H, m), 1.84 (1H, m), 3.14 (1H, m), 3.30 (1H, m), 4.01, (1H, m), 4.60 (1H, m), 7.20 (1H, t, J=8.57), 7.38 (1H, m), 7.68-7.42 (4H, m), 8.18 (2H, m), 8.28 (1H, s), 8.44 (1H, d, J=8.81 Hz). m/z 387.5 (MH+).

Source