Hydrochloric Acid → 3-Methoxy-8,9-methylenedioxydibenzo[c,h]cinnoline

HRID 1582892Notes

Reaction equation

HRID 1582892 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]2[O:8][CH2:9][O:10][C:5]2=[CH:4][C:3]=1[C:11]1[CH:20]=[C:19]2[C:14]([CH:15]=[CH:16][C:17]([O:21][CH3:22])=[CH:18]2)=[CH:13][CH:12]=1.Cl.[N:24]([O-])=O.[Na+].O>C(O)(=O)C>[CH3:22][O:21][C:17]1[CH:16]=[CH:15][C:14]2=[CH:13][CH:12]=[C:11]3[C:20]([N:24]=[N:1][C:2]4[CH:7]=[C:6]5[O:8][CH2:9][O:10][C:5]5=[CH:4][C:3]3=4)=[C:19]2[CH:18]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 227164427-(2-Amino-4,5-methylenedioxyphenyl)-2-methoxynaphthaleneHCID 23668193Sodium Nitrite

Product 1

HCID 98829143-Methoxy-8,9-methylenedioxydibenzo[c,h]cinnolineYield 83%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

7-(2-Amino-4,5-methylenedioxyphenyl)-2-methoxynaphthalene 49 (70 mg, 0.24 mmol) was dissolved in acetic acid (2.0 mL) and concentrated hydrochloric acid (0.4 mL). The solution was cooled in an ice bath and diazotized by the dropwise addition of a solution of sodium nitrite (0.16 g in 1.6 mL water). The resulting diazonium solution was allowed to warm slowly to room temperature and left overnight. To the resulting red solution containing some precipitate was added 50 mL water and the reaction mixture was extracted with ethyl acetate (30 mL×3). The organic layers were combined and washed with diluted sodium hydroxide solution first, then with water and brine. The organic layer was dried over anhydrous sodium sulfate and evaporated in vacuo. The crude product was purified by column chromatography on silica gel using 55:45 hexanes:ethyl acetate to give compound 44 (60 mg 83%); mp 259-261° C.; IR (KBr) 2923, 1612, 1498, 1468, 1234, 1199 cm−1; UV (MeOH) 270, 250, 228 nm (log ε=4.68, 4.37, 4.44); 1H NMR (CDCl3) δ4.12 (3H, s), 6.24 (2H, s), 7.37 (1H, dd, J1=8.8, J2=2.7), 7.80 (1H, s), 7.88 (1H, d, J=8.8), 7.96 (1H, s), 8.03 (1H, d, J=9.1), 8.09 (1H, d, J=9.0), 9.15 (1H, d, J=2.7); 13C NMR δ56.32, 98.31, 102.93, 104.03, 107.49, 116.36, 120.40, 120.50, 121.09, 127.96, 130.00, 132.54, 133.34, 141.99, 146.10, 150.53, 152.09, 160.28; HRMS (EI) calcd for C18H12N2O3 m/z: 304.0848; found: 304.0852.

Workup

  1. temperatureThe solution was cooled in an ice bath
  2. additionTo the resulting red solution containing some precipitate
  3. extractionthe reaction mixture was extracted with ethyl acetate (30 mL×3)
  4. washwashed with diluted sodium hydroxide solution first
  5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  6. customevaporated in vacuo
  7. customThe crude product was purified by column chromatography on silica gel using 55:45 hexanes

Sources & evidence

ORD record
ord-c0e5bef820424966a7d21d755aba904c
Source dataset
uspto-grants-2004_05
Patent number
US06740650B2

Reaction notes

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