Sodium Carbonate → 5-(3,4-Dimethylphenyl)pyrazin-2-amine

HRID 2406063Notes

Reaction equation

HRID 2406063 reaction equation
Br[C:2]1[N:3]=[CH:4][C:5]([NH2:8])=[N:6][CH:7]=1.[CH3:9][C:10]1[CH:11]=[C:12](B(O)O)[CH:13]=[CH:14][C:15]=1[CH3:16].C(=O)([O-])[O-].[Na+].[Na+]>O1CCOCC1.CO.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH3:9][C:10]1[CH:11]=[C:12]([C:2]2[N:3]=[CH:4][C:5]([NH2:8])=[N:6][CH:7]=2)[CH:13]=[CH:14][C:15]=1[CH3:16]

Participants

8

Reactant 3

HCID 10340Sodium CarbonateHCID 5995392-Amino-5-bromopyrazineHCID 27343483,4-Dimethylphenylboronic acid

Product 1

HCID 655500745-(3,4-Dimethylphenyl)pyrazin-2-amine

Reagents, catalysts & solvents 4

HCID 178418397HCID 178418397, compoundCatalystHCID 887MethanolSolventHCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
110 °C

Procedure

To a solution of 5-bromopyrazin-2-amine (4 g, 22.99 mmol, 1.00 equiv) in 1,4-dioxane (68 mL) and methanol (23 mL) was added 3,4-dimethylphenylboronic acid (3.52 g, 23.47 mmol, 1.02 equiv), sodium carbonate (4.872 g, 45.96 mmol, 2.00 equiv) in water (23 mL), and Pd(PPh3)4 (532 mg, 0.46 mmol, 0.02 equiv) and the resulting solution was stirred for 4.5 h at 110° C. in an oil bath. The resulting mixture was concentrated under vacuum, diluted with 200 mL of ethyl acetate, washed with 2×100 mL of brine, dried over anhydrous sodium sulfate and then concentrated under vacuum. The residue was applied onto a silica gel column with petroleum ether/ethyl acetate=10:1˜1:1, then with dichloromethane/methanol (10:1˜5:1). The collected fractions were combined and concentrated under vacuum. This resulted in 4.82 g (crude) of 5-(3,4-dimethylphenyl)pyrazin-2-amine as a yellow solid.

Workup

  1. concentrationThe resulting mixture was concentrated under vacuum
  2. additiondiluted with 200 mL of ethyl acetate
  3. washwashed with 2×100 mL of brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated under vacuum
  6. concentrationconcentrated under vacuum
  7. customThis resulted in 4.82 g (crude) of 5-(3,4-dimethylphenyl)pyrazin-2-amine as a yellow solid

Sources & evidence

ORD record
ord-f029186c36bf47b786bc3c30c7209427
Source dataset
uspto-grants-2014_08
Patent number
US08809339B2

Reaction notes

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