Potassium Carbonate → 8-Bromo-1,2,3,4-tetrahydronapthyridine

HRID 1861683Notes

Reaction equation

HRID 1861683 reaction equation
[NH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][N:9]=2)[CH2:4][CH2:3][CH2:2]1.[Br:11]N1C(=O)CCC1=O.C([O-])([O-])=O.[K+].[K+]>C(O)(=O)C>[Br:11][N:9]1[C:10]2[NH:1][CH2:2][CH2:3][CH2:4][C:5]=2[CH:6]=[CH:7][CH2:8]1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 67184N-bromobutanimideHCID 130473671,2,3,4-Tetrahydro-1,8-naphthyridine

Product 1

HCID 865841748-Bromo-1,2,3,4-tetrahydronapthyridine

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a solution of 0.6730 g (5.02 mmol) 32 in 20 mL glacial acetic acid was added 1.0701 g (6.01 mmol) N-bromosuccinimide. After 16 h at 65° C., the reaction mixture was cooled to room temperature and poured onto 50 mL ice water. This was brought to pH 11 with K2CO3 and extracted with 4×100 mL CHCl3. The combined CHCl3 extracts were washed with 100 mL brine, dried over Na2SO4, filtered and concentrated in vacuo. Purification by flash chromatography (50×115 mm silica gel, linear gradient 2-5% (10% NH4H:MeOH):CH2Cl2) yielded 33. 1H NMR (CDCl3, 400 MHz) δ 8.175 (s, 1H, ArH); 7.877 (s, 1H, ArH); 3.458-3.423 (m, 2H, CH2); 2.725 (t, 2H, J=6.26 Hz, CH2); 1.970-1.911 (m, 2H, CH2); MS (Electrospray): m/z 212.9, 214.8 (M+H, 79Br, 81Br).

Workup

  1. extractionextracted with 4×100 mL CHCl3
  2. washThe combined CHCl3 extracts were washed with 100 mL brine
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customPurification by flash chromatography (50×115 mm silica gel, linear gradient 2-5% (10% NH4H:MeOH):CH2Cl2)

Sources & evidence

ORD record
ord-f0057b796b874921a888db3bf6e4eb38
Source dataset
uspto-grants-2003_03
Patent number
US06534510B2

Reaction notes

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