Reaction #632028

Reaction equation

1,4-ethano-8-phenyl-1,2,3,4-tetrahydro-1,5-naphthyridin-6-one

DMF

thionyl chloride

→

6-chloro-1,4-ethano-8-phenyl-1,2,3,4-tetrahydro-1,5-naphthyridine

Yield 66.0%

Conditions

Workup

1. 1
   Concentrationconcentrated in vacuo
2. 2
   workup.ADDITIONThe residue was poured on ice-water and saturated aq. NaHCO3 solution
3. 3
   workup.ADDITIONwas added
4. 4
   ExtractionThe mixture was extracted with EtOAc (2×50 mL)
5. 5
   Dryingdried over Na2SO4
6. 6
   Concentrationconcentrated
7. 7
   Otherpurified by flash chromatography (EtOAc:hexane, 1:4)

Procedure

To a solution of 1,4-ethano-8-phenyl-1,2,3,4-tetrahydro-1,5-naphthyridin-6-one (435 mg, 1.72 mmol) in 2.5 ml of thionyl chloride was added 100 μL of DMF, and the reaction mixture was heated at 70° C. for 10 h, and concentrated in vacuo. The residue was poured on ice-water and saturated aq. NaHCO3 solution was added to adjust pH to 10-11. The mixture was extracted with EtOAc (2×50 mL), dried over Na2SO4, concentrated and purified by flash chromatography (EtOAc:hexane, 1:4) to give 6-chloro-1,4-ethano-8-phenyl-1,2,3,4-tetrahydro-1,5-naphthyridine (310 mg, 66%) as a white solid; 1H NMR (CDCl3, 300 MHz) 7.58 (m, 2H), 7.43 (m, 3H), 7.29 (s, 1H), 3.35 (s, 1H), 3.18 (m, 2H), 2.63 (m, 2H), 1.99 (m, 2H), 1.73 (m, 2H) ppm; MS (ES) 271.39 (M+H).

Source