Potassium Carbonate → Pyrazino[2,3-c]quinolin-5-amine

HRID 340182Notes

Reaction equation

HRID 340182 reaction equation
C(OC([NH:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1B(O)O)=O)(C)(C)C.Cl[C:19]1[C:20]([C:25]#[N:26])=[N:21][CH:22]=[CH:23][N:24]=1.C(=O)([O-])[O-].[K+].[K+]>C1(C)C=CC=CC=1.CO.ClCCl.O>[N:24]1[C:19]2[C:14]3[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=3[N:8]=[C:25]([NH2:26])[C:20]=2[N:21]=[CH:22][CH:23]=1

Participants

8

Reactant 3

HCID 11430Potassium CarbonateHCID 2924653-Chloropyrazine-2-carbonitrileHCID 2773226(2-BOC-aminophenyl)boronic acid

Product 1

HCID 58213747Pyrazino[2,3-c]quinolin-5-amine

Reagents, catalysts & solvents 4

HCID 887MethanolSolventHCID 962WaterSolventHCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
100 °C

Procedure

A solution of 2-(tert-butoxycarbonylamino)phenylboronic acid (1.0 eq.) and 3-chloropyrazine-2-carbonitrile (1.0 eq.) in toluene (0.44 M) was mixed with tetrakis(triphenyl-phosphine)palladium (5 mol %) and 2N aqueous potassium carbonate solution (2.0 eq.). The reaction was heated to 100° C. and stirred overnight. After cooling to ambient temperature, the reaction content was diluted with 2% methanol in dichloromethane and water. The two phases were separated, and the aqueous layer was extracted twice with 2% methanol in dichloromethane. The combined organic layers were washed with brine, dried over anhydrous MgSO4, and concentrated en vacuo. The crude product was purified by flash chromatography on a COMBIFLASH® system (ISCO) using 0-50% ethyl acetate in hexane to give a solid. 1H NMR (acetone d-6): δ 9.14 (s, 1H), 8.95 (s, 1H), 8.77 (d, 1H), 7.63-7.66 (m, 2H), 7.38 (t, 1H), 6.77 (br, 2H). LRMS [M+H]=197.1

Workup

  1. temperatureAfter cooling to ambient temperature
  2. customThe two phases were separated
  3. extractionthe aqueous layer was extracted twice with 2% methanol in dichloromethane
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over anhydrous MgSO4
  6. concentrationconcentrated en vacuo
  7. customThe crude product was purified by flash chromatography on a COMBIFLASH® system (ISCO)
  8. customto give a solid

Sources & evidence

ORD record
ord-328bbb2683bf4e94b5d867507ecae260
Source dataset
uspto-grants-2014_11
Patent number
US08895577B2

Reaction notes

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