7H-Naphtho(1,2,3-ij)(2,7)naphthyridin-7-one → 4-Bromosampangine

HRID 653617Notes

Reaction equation

HRID 653617 reaction equation
C1C=C[NH+]=CC=1.[Br:7][Br-]Br.[CH:10]1[CH:11]=[CH:12][C:13]2[C:26](=[O:27])[C:25]3[C:17]4[C:18]([CH:22]=[CH:23][N:24]=3)=[CH:19][CH:20]=[N:21][C:16]=4[C:14]=2[CH:15]=1.C(=O)(O)[O-].[Na+]>C(Cl)(Cl)Cl>[CH:10]1[CH:15]=[C:14]2[C:16]3[C:17]4[C:25]([C:26](=[O:27])[C:13]2=[CH:12][CH:11]=1)=[N:24][CH:23]=[C:22]([Br:7])[C:18]=4[CH:19]=[CH:20][N:21]=3

Participants

4

Procedure

A mixture of pyridinium bromide perbromide (390 mg, 1.2 mmol) and sampangine, (232 mg, 1.0 mmol) in chloroform (12 mL) was heated at reflux for 15 h. Saturated sodium bicarbonate solution (100 mL) was added to the cooled reaction and the mixture stirred vigorously for 30 min. The two layers were separated and the aqueous phase extracted with chloroform (2×30 mL). The combined organic layers were dried over potassium carbonate and concentrated to dryness. The residual solid was applied to a 2×40 cm column of silica gel (Merck 230-400 mesh) and the pure product (200 mg, 64%) eluted with chloroform, mp 180° C. dec. IR (KBr) 1670, 1590, 1400, 1320, 1310, 1275, 1230, 980, 790, 755, 720 cm-1 ; 1H NMR (CDCl3) δ 9.28 (s, 1 H), 8.99 (d, J=5.9 Hz, 1 H), 8.85 (dd, J= 7.9, 1.4 Hz, 1 H), 8.46 (dd, J=7.9, 1.4 Hz, 1 H), 7.96 (d, J=5.9 Hz, 1 H), 7.86 (ddd, J=7.7, 7.9, 1.4 Hz, 1 H), 7.72 (ddd, J=7.9, 7.9, 1.4 Hz, 1 H); 13C NMR (CDCl3) 181.6 (0), 151.7 (0), 150.2 (1), 148.6 (1), 146.7 (0), 138.6 (0), 135.1 (0), 135.0 (1), 132.3 (0), 131.8 (1), 128.7 (1), 125.8 (1), 123.7 (0), 120.5 (0), 118.3 (1) ppm; HR MS calc. for C15H7BrN2O 309.9741, found 309.9747.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 15 h
  3. customThe two layers were separated
  4. extractionthe aqueous phase extracted with chloroform (2×30 mL)
  5. dry with materialThe combined organic layers were dried over potassium carbonate
  6. concentrationconcentrated to dryness
  7. washthe pure product (200 mg, 64%) eluted with chloroform, mp 180° C. dec

Sources & evidence

ORD record
ord-5405584e990045e286739362330a78fa
Source dataset
uspto-grants-1992_07
Patent number
US05128344

Reaction notes

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