(2-Methylpropyl)boronic acid → 4,4,5,5-Tetramethyl-2-(2-methylpropyl)-1,3,2-dioxaborolane

HRID 485637Notes

Reaction equation

HRID 485637 reaction equation
[CH3:1][CH:2]([CH3:7])[CH2:3][B:4]([OH:6])[OH:5].O.O.O.O.O.O.O[C:15]([C:18](O)([CH3:20])[CH3:19])([CH3:17])[CH3:16]>CCOCC.CCCCCC>[CH3:16][C:15]1([CH3:17])[C:18]([CH3:20])([CH3:19])[O:6][B:4]([CH2:3][CH:2]([CH3:7])[CH3:1])[O:5]1

Participants

5

Reactant 2

HCID 2734395(2-Methylpropyl)boronic acidHCID 20268938Pinacol hexahydrate

Product 1

HCID 134912534,4,5,5-Tetramethyl-2-(2-methylpropyl)-1,3,2-dioxaborolaneYield 48.4%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8058HexaneSolvent

Procedure

A solution of 50.13 g (0.494 mol) of 2-methylpropylboronic acid in 300 mL of ether, prepared by a procedure substantially similar to the foregoing, was contacted with 112.63 g (0.494 mol) of pinacol hexahydrate and stirred for 24 hours. At the end of this period, the resulting reaction mixture was diluted with 500 mL of hexane. A top layer formed which was separated from the rest of the mixture and contacted with 18 mL of water. After stirring for 15 minutes, 9.52 g of a solid separated, which was removed by filtration. The remaining hexane layer was dried over Na2SO4 and residual solvent was removed by evaporation. The remaining material was then distilled using a 6" spinning band distillation column, to obtain 43.98 g (0.239 mol, 48.4%) of an oil, bp: 65°-72°/13 mm, 1H NMR (90 MHz, CDCl3): δ0.65 (d, J=6.6 Hz, 2), 0.93 (d, J=6.6 Hz, 6), 1.25 (s, 12), 1.86 (hep, J=6.6 Hz, 1); Anal. Calcd. for C10H21O2B: C, 65.25; H, 11.50; B, 5.87; Found: C, 65.07, H, 11.52; B, 6.01.

Workup

  1. customAt the end of this period, the resulting reaction mixture
  2. customA top layer formed which
  3. customwas separated from the rest of the mixture
  4. stirringAfter stirring for 15 minutes
  5. custom9.52 g of a solid separated
  6. customwhich was removed by filtration
  7. dry with materialThe remaining hexane layer was dried over Na2SO4 and residual solvent
  8. customwas removed by evaporation
  9. distillationThe remaining material was then distilled
  10. distillationband distillation column

Sources & evidence

ORD record
ord-a512926db46e401dbbce52be89191238
Source dataset
uspto-grants-1985_08
Patent number
US04537773

Reaction notes

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