2-Amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine → 3-Amino-2-benzyl-8-methoxybenzo[f]quinoxaline

HRID 873032Notes

Reaction equation

HRID 873032 reaction equation
[NH2:1][C:2]1[C:7]([CH2:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[N:6][C:5]([C:15]2[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][C:16]=2C=C)=[C:4]([CH:25]=[CH2:26])[N:3]=1>CC1C=C(C)C(N2C(=[Ru](Cl)(Cl)=CC3C=CC=CC=3OC(C)C)N(C3C(C)=CC(C)=CC=3C)CC2)=C(C)C=1.ClCCCl>[NH2:1][C:2]1[C:7]([CH2:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[N:6][C:5]2[C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][C:16]=3[CH:26]=[CH:25][C:4]=2[N:3]=1

Participants

4

Reactant 1

HCID 706628152-Amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine

Product 1

HCID 706627993-Amino-2-benzyl-8-methoxybenzo[f]quinoxalineYield 25.4%

Reagents, catalysts & solvents 2

HCID 11763533(1,3-Bis(2,4,6-trimethylphenyl)imidazolidin-2-ylidene)(dichloro)((2-((propan-2-yl)oxy)phenyl)methylidene)rutheniumCatalystHCID 111,2-DichloroethaneSolvent

Conditions

Temperature
90 °C

Procedure

Under an argon atmosphere, to a solution of Hoveyda-Grubbs second generation catalyst (84.5 mg, 135 μmol) in 1,2-dichloroethane (100 mL) was added 2-amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine (9) (585 mg, 1.70 mmol) at room temperature. The mixture was then heated to 90° C. and stirred overnight (17 hours). After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was purified by silica gel flash column chromatography (n-hexane/ethyl acetate=3/1→2/1) to give 3-amino-2-benzyl-8-methoxybenzo[f]quinoxaline (12) as a white solid (136 mg, 431 μmol, 25.3%). TLC Rf=0.64 (n-hexane/ethyl acetate=1/1); 1H NMR (500 MHz, CDCl3) δ 3.98 (s, 3H), 4.39 (s, 2H), 4.63 (s, 2H), 7.21-7.38 (m, 7H), 7.63 (d, 1H, J=9.0 Hz), 7.85 (d, 1H, J=9.0 Hz), 9.00 (d, 1H, J=9.0 Hz); 13C NMR (126 MHz, CDCl3) δ 41.8, 55.4, 107.5, 118.1, 124.9, 125.5, 125.8, 127.2, 128.7 (2C), 129.1 (2C), 130.1, 132.7, 134.6, 136.6, 138.9, 143.1, 151.2, 158.5.

Workup

  1. temperatureAfter cooling to room temperature
  2. concentrationthe mixture was concentrated under reduced pressure
  3. customThe residue was purified by silica gel flash column chromatography (n-hexane/ethyl acetate=3/1→2/1)

Sources & evidence

ORD record
ord-8017c1de2a7c4e7ea3a926a96a917d5a
Source dataset
uspto-grants-2015_03
Patent number
US08975403B2

Reaction notes

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