Water → 2,3,8,9-Tetramethoxy-dibenzo[c,h]cinnoline

HRID 1582874Notes

Reaction equation

HRID 1582874 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[C:5]([O:10][CH3:11])=[CH:4][C:3]=1[C:12]1[CH:13]=[C:14]2[C:19](=[CH:20][CH:21]=1)[CH:18]=[C:17]([O:22][CH3:23])[C:16]([O:24][CH3:25])=[CH:15]2.[N:26]([O-])=O.[Na+].O.C(Cl)(Cl)Cl>C(O)(=O)C.Cl.C(OCC)(=O)C>[CH3:23][O:22][C:17]1[C:16]([O:24][CH3:25])=[CH:15][C:14]2[C:19]([CH:18]=1)=[CH:20][CH:21]=[C:12]1[C:13]=2[N:26]=[N:1][C:2]2[CH:7]=[C:6]([O:8][CH3:9])[C:5]([O:10][CH3:11])=[CH:4][C:3]1=2

Participants

8

Reactant 4

HCID 962WaterHCID 6212ChloroformHCID 227164342-(6,7-Dimethoxynaphthalen-2-yl)-4,5-dimethoxyanilineHCID 23668193Sodium Nitrite

Product 1

HCID 227164282,3,8,9-Tetramethoxy-dibenzo[c,h]cinnolineYield 44%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 313Hydrochloric AcidSolventHCID 8857Ethyl AcetateSolvent

Procedure

6-(2-Amino-4,5-dimethoxyphenyl)-2,3-dimethoxynaphthalene (18) (11 mg, 0.033 mmol) in acetic acid (0.6 mL) and concentrated hydrochloric acid (0.06 mL) was cooled to 0° C. and diazotised with a solution of sodium nitrite (0.026 g in 0.5 mL water). The diazonium solution was allowed to rise slowly to room temperature and left overnight. Water (30 mL) was added to the red solution with some precipitate. The resulting mixture was extracted with ethyl acetate, washed with diluted sodium hydroxide solution, then with water, dried (anhydrous Na2SO4) and rotaevaporated to give the crude product. Chromatography on silica gel using 40:60 chloroform:ethyl acetate afforded the title compound (5 mg) in 44% yield; 1H NMR (CDCl3) d 4.09(3H, s), 4.18(6H, s), 4.23(3H, s), 7.31(1H, s), 7.74(1H, s), 8.00(1H, s), 8.01(1H, d, J=8.5), 8.20(1H, d, J=8.9), 9.15(1H, s); 13C NMR d 56.5, 56.9, 99.9, 104.5, 107.9, 109.5, 116.9, 118.5, 118.9, 127.0, 128.4, 131.6, 141.8, 144.6, 151.1, 151.2, 152.0, 153.9.

Workup

  1. customto rise slowly to room temperature
  2. extractionThe resulting mixture was extracted with ethyl acetate
  3. washwashed with diluted sodium hydroxide solution
  4. dry with materialwith water, dried (anhydrous Na2SO4)
  5. customto give the crude product

Sources & evidence

ORD record
ord-d232576d7be043ada6b0c074c84c528c
Source dataset
uspto-grants-2004_05
Patent number
US06740650B2

Reaction notes

Loading…