2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → HCID 57668735, compound

HRID 579676Notes

Reaction equation

HRID 579676 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH2:15][CH:16]([CH3:18])[CH3:17])[C:7]3[C:12]([C:13]=2[CH:14]=1)=[CH:11][CH:10]=[CH:9][CH:8]=3.[Li]CCCC.C(O[B:28]1[O:32][C:31]([CH3:34])([CH3:33])[C:30]([CH3:36])([CH3:35])[O:29]1)(C)C>C1COCC1>[CH3:17][CH:16]([CH3:18])[CH2:15][N:6]1[C:5]2[CH:4]=[CH:3][C:2]([B:28]3[O:32][C:31]([CH3:34])([CH3:33])[C:30]([CH3:36])([CH3:35])[O:29]3)=[CH:14][C:13]=2[C:12]2[C:7]1=[CH:8][CH:9]=[CH:10][CH:11]=2

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 57668844HCID 57668844, compoundHCID 178418339Butyllithium

Product 1

HCID 57668735HCID 57668735, compoundYield 81.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Into a solution of 3 (4.2 g, 13.9 mmol) in THF (80 ml) was added BuLi (2.5 M in hexane, 6.95 ml, 17.4 mmol) dropwise at −78° C. The mixture was stirred at this temperature for 3 hours before 2-isopropoxy-4,4,5,5-tetramethyl-[1,3,2]-dioxaborolane (4.05 g, 21.75 mmol) was added in one portion. The reaction mixture was allowed to warm up to room temperature over a period of 12 hours, quenched with water, and then extracted with ether. The organic extracts were combined, washed with brine and water, and dried over MgSO4. Upon evaporating off the solvent, the crude product was purified by column chromatography on silica gel with hexane/methylene chloride 3:1 (v/v) as the eluent to yield 4 (3.95 g, 81%) as a white powder. 1H NMR (400 MHz, CDCl3, 298 K): δ(ppm) 8.60 (s, 1H), 8.15-8.10 (d, 1H), 7.90-7.85 (d, 1H), 7.45-7.35 (m, 3H), 7.25-7.15 (m, 1H), 4.10-4.09 (d, 2H), 2.42-2.30 (m, 1H), 1.39 (s, 12H), 0.97-0.95 (d, 6H).

Workup

  1. additionwas added in one portion
  2. customquenched with water
  3. extractionextracted with ether
  4. washwashed with brine and water
  5. dry with materialdried over MgSO4
  6. customUpon evaporating off the solvent
  7. customthe crude product was purified by column chromatography on silica gel with hexane/methylene chloride 3:1 (v/v) as the eluent

Sources & evidence

ORD record
ord-67284fd1e041443c99fb1e0ba929e401
Source dataset
uspto-grants-2015_05
Patent number
US09040718B2

Reaction notes

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