Hydrochloric Acid → (5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)boronic acid

HRID 858263Notes

Reaction equation

HRID 858263 reaction equation
[CH3:1][C:2]1([CH3:15])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[C:6](Br)[CH:5]=[CH:4][C:3]1=2.C([Li])CCC.[B:21](OC(C)C)([O:26]C(C)C)[O:22]C(C)C.Cl>C1COCC1>[CH3:1][C:2]1([CH3:15])[CH2:11][CH2:10][C:9]([CH3:13])([CH3:12])[C:8]2[CH:7]=[C:6]([B:21]([OH:26])[OH:22])[CH:5]=[CH:4][C:3]1=2

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 21531Triisopropyl borateHCID 2266856-Bromo-1,1,4,4-tetramethyl-1,2,3,4-tetrahydronaphthaleneHCID 178418339Butyllithium

Product 1

HCID 10353857(5,5,8,8-Tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)boronic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

21.38 g (80.0 mmol) of 5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-bromonaphthalene and 50 ml of THF are introduced into a three-necked flask under a stream of nitrogen. 38.4 ml (96.0 mmol) of n-butyllithium (2.5 M in hexane) are added dropwise, at −78° C., and the mixture is stirred for one hour. 27.7 ml (120.0 mmol) of triisopropyl borate are added dropwise at this same temperature and the mixture is stirred for 2 hours. 350 ml of hydrochloric acid (1 N) are added at −50° C. and the mixture is allowed to warm to room temperature. The reaction medium is extracted with dichloromethane and the organic phase is separated out after settling has taken place, dried over magnesium sulphate and evaporated. 18.60 g (100%) of the expected boronic acid are collected in the form of an oil which crystallizes slowly. Melting point 190–192° C.

Workup

  1. stirringthe mixture is stirred for 2 hours
  2. extractionThe reaction medium is extracted with dichloromethane
  3. customthe organic phase is separated out after settling
  4. dry with materialdried over magnesium sulphate
  5. customevaporated
  6. custom18.60 g (100%) of the expected boronic acid are collected in the form of an oil which
  7. customcrystallizes slowly

Sources & evidence

ORD record
ord-e33e3d049de54c90a613e71b7c64c9e1
Source dataset
uspto-grants-2006_12
Patent number
US07148245B2

Reaction notes

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