Pinacol → 2,4-Dimethoxypyrimidine-5-boronic acid pinacol ester

HRID 2375589Notes

Reaction equation

HRID 2375589 reaction equation
[CH3:1][O:2][C:3]1[N:8]=[C:7]([O:9][CH3:10])[C:6]([B:11]([OH:13])[OH:12])=[CH:5][N:4]=1.O[C:15]([C:18](O)([CH3:20])[CH3:19])([CH3:17])[CH3:16]>O1CCCC1>[CH3:1][O:2][C:3]1[N:8]=[C:7]([O:9][CH3:10])[C:6]([B:11]2[O:12][C:18]([CH3:20])([CH3:19])[C:15]([CH3:17])([CH3:16])[O:13]2)=[CH:5][N:4]=1

Participants

4

Reactant 2

HCID 6425PinacolHCID 2736209(2,4-Dimethoxypyrimidin-5-yl)boronic acid3×

Product 1

HCID 162183882,4-Dimethoxypyrimidine-5-boronic acid pinacol ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a 100 mL round-bottomed flask charged with 4 Å molecular sieves (approximately 1 g) was added the 2,4-dimethoxypyrimidine-5-boronic acid (5.34 g, 29.0 mmol) and anhydrous tetrahydrofuran (25 mL). The pinocol (2.98 g, 25.3 mmol) was added and the reaction stirred at room temperature for 1.5 hours. Additional 2,4-dimethoxypyrimidine-5-boronic acid (662.2 mg, 3.6 mmol) was added and the reaction stirred overnight. Molecular sieves and 2,4-dimethoxypyrimidine-5-boronic acid (1.53 g, 8.3 mmol) were added and the reaction stirred for 0.5 hours. Pinacol (0.613 g, 5.2 mmol) was then added. After 2 hours, the molecular sieves were removed by filtration and the filtrate was concentrated. After drying under high vacuum, the title compound was obtained as a fine yellow solid (8.61 g, 79%). 1H NMR (300.132 MHz, CDCl3) δ 8.56 (s, 1H), 4.01 (d, J=1.5 Hz, 6H), 1.34 (s, 12H).

Workup

  1. additionTo a 100 mL round-bottomed flask charged with 4 Å molecular sieves (approximately 1 g)
  2. additionThe pinocol (2.98 g, 25.3 mmol) was added
  3. stirringthe reaction stirred overnight
  4. stirringthe reaction stirred for 0.5 hours
  5. waitAfter 2 hours
  6. customthe molecular sieves were removed by filtration
  7. concentrationthe filtrate was concentrated
  8. customAfter drying under high vacuum

Sources & evidence

ORD record
ord-bf494e1d4bf3494fbbf8f5566ee82d91
Source dataset
uspto-grants-2008_12
Patent number
US07465795B2

Reaction notes

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