Phenylboronic Acid → 5-Bromo-3-phenylpyrazin-2-amine

HRID 2197566Notes

Reaction equation

HRID 2197566 reaction equation
Br[C:2]1[C:3]([NH2:9])=[N:4][CH:5]=[C:6]([Br:8])[N:7]=1.[C:10]1(B(O)O)[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>C1(C)C=CC=CC=1>[Br:8][C:6]1[N:7]=[C:2]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[C:3]([NH2:9])=[N:4][CH:5]=1

Participants

4

Reactant 2

HCID 66827Phenylboronic AcidHCID 6200042-Amino-3,5-dibromopyrazine

Product 1

HCID 457909085-Bromo-3-phenylpyrazin-2-amineYield 95%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 3,5-dibromopyrazin-2-amine (214 mg, 0.83 mmol) and phenyl boronic acid (100 mg, 0.8 mmol) in toluene (8 mL) was degassed and backfilled with nitrogen 3 times. Pd(PPh3)4 (46 mg) was added followed by 2M K3PO4 (0.8 mL) and EtOH (1 mL). The mixture was heated at reflux for 18 h. The solution was cooled to room temperature, partitioned between EtOAc (25 mL) and water (5 mL). The layers were separated and the organic layer dried over Na2SO4, filtered and concentrated to an oil which was purified via silica gel chromatography (15% EtOAc/heptane) to afford the product (187 mg, 95% yield).

Workup

  1. customwas degassed
  2. additionPd(PPh3)4 (46 mg) was added
  3. temperatureThe mixture was heated
  4. temperatureat reflux for 18 h
  5. custompartitioned between EtOAc (25 mL) and water (5 mL)
  6. customThe layers were separated
  7. dry with materialthe organic layer dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated to an oil which
  10. customwas purified via silica gel chromatography (15% EtOAc/heptane)

Sources & evidence

ORD record
ord-5b0b76d8f86a42b597b704291bd30cd1
Source dataset
uspto-grants-2012_12
Patent number
US08338604B2

Reaction notes

Loading…