Hydrochloric Acid → 6-Hexyloxypyridine-3-boronic acid

HRID 376753Notes

Reaction equation

HRID 376753 reaction equation
C([Li])CCC.Br[C:7]1[CH:8]=[CH:9][C:10]([O:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH3:19])=[N:11][CH:12]=1.[B:20](OC)([O:23]C)[O:21]C.Cl>O.C(OCC)C>[CH2:14]([O:13][C:10]1[CH:9]=[CH:8][C:7]([B:20]([OH:23])[OH:21])=[CH:12][N:11]=1)[CH2:15][CH2:16][CH2:17][CH2:18][CH3:19]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 221180785-Bromo-2-hexyloxypyridineHCID 178418339Butyllithium

Product 1

HCID 221125716-Hexyloxypyridine-3-boronic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

250 mmol of n-butyllithium (1.6M solution in n-hexane) are added dropwise at 0° C. with exclusion of moisture and under a protective-gas atmosphere to a solution of 250 mmol of 5bromo-2-hexyloxypyridine in 500 ml of abs. diethyl ether. The mixture is stirred at this temperature for a further 1 hour, and 275 mmol of trimethyl borate are subsequently added slowly. After the mixture has been stirred at 0° C. for a further hour, a solution of 175 ml of water and 25 ml of 37 percent hydrochloric acid is added dropwise. The mixture is stirred at room temperature for 1 hour, the phases are then separated, the aqueous phase is extracted a number of times with dichloromethane, and the combined organic extracts are dried using magnesium sulfate. The solvents are removed in vacuo. After drying in a high vacuum, the red-brown, high-viscosity crude product is reacted further without additional purification.

Workup

  1. stirringAfter the mixture has been stirred at 0° C. for a further hour
  2. stirringThe mixture is stirred at room temperature for 1 hour
  3. customthe phases are then separated
  4. extractionthe aqueous phase is extracted a number of times with dichloromethane
  5. customthe combined organic extracts are dried
  6. customThe solvents are removed in vacuo
  7. customAfter drying in a high vacuum
  8. customthe red-brown, high-viscosity crude product is reacted further without additional purification

Sources & evidence

ORD record
ord-50185cdd3bd341b492f931a4b5d05d8c
Source dataset
uspto-grants-2000_02
Patent number
US06022492

Reaction notes

Loading…