Hydrochloric Acid → (6-Methoxy-1-benzothiophen-2-yl)boronic acid

HRID 341860Notes

Reaction equation

HRID 341860 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[CH:10]=[CH:9][S:8][C:7]=2[CH:11]=1.C([Li])CCC.[B:17](OC(C)C)([O:22]C(C)C)[O:18]C(C)C.Cl>O1CCCC1.C(OCC)(=O)C>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[CH:10]=[C:9]([B:17]([OH:22])[OH:18])[S:8][C:7]=2[CH:11]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 21531Triisopropyl borateHCID 136342376-Methoxy-1-benzothiopheneHCID 178418339Butyllithium

Product 1

HCID 10560276(6-Methoxy-1-benzothiophen-2-yl)boronic acidYield 71%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 6-methoxybenzo[b]thiophene (18.13 g, 0.111 mol) in 150 mL of anhydrous tetrahydrofuran (THF) at -60° C. was added n-butyllithium (76.2 mL, 0.122 mol, 1.6M solution in hexanes), dropwise via syringe. After stirring for 30 minutes, triisopropyl borate (28.2 mL, 0.122 mol) was introduced via syringe. The resulting mixture was allowed to gradually warm to 0° C. and then distributed between 1N hydrochloric acid and ethyl acetate (300 mL each). The layers were separated, and the organic layer was dried over sodium sulfate. Concentration in vacuo produced a white solid that was triturated from ethyl ether hexanes. Filtration provided 16.4 g (71%) of 6-methoxybenzo[b]thiophene-2-boronic acid as a white solid. mp 200° C. (dec).

Workup

  1. customThe layers were separated
  2. dry with materialthe organic layer was dried over sodium sulfate
  3. concentrationConcentration in vacuo
  4. customproduced a white solid
  5. customthat was triturated from ethyl ether hexanes
  6. filtrationFiltration

Sources & evidence

ORD record
ord-4a068e88ba474927b3047881ce32bdbb
Source dataset
uspto-grants-1999_01
Patent number
US05856339

Reaction notes

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