Sulfuric Acid → B-(6-Amino-2-naphthalenyl)boronic acid

HRID 2378554Notes

Reaction equation

HRID 2378554 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[C:7](Br)[CH:8]=2)[CH:3]=1.BrC1C=CC2C(=CC=C(O)C=2)C=1.[H-].[K+].C([Li])(C)(C)C.[B:32](OC(C)C)([O:37]C(C)C)[O:33]C(C)C.S(=O)(=O)(O)O>C1COCC1.CCCCC.O>[NH2:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([B:32]([OH:37])[OH:33])[CH:6]=[CH:5]2

Participants

10

Reactant 6

HCID 1118Sulfuric AcidHCID 21531Triisopropyl borateHCID 271446-Bromo-2-naphthalenolHCID 82127Potassium hydrideHCID 3484042-Amino-6-bromonaphthaleneHCID 178418306HCID 178418306, compound

Product 1

HCID 22558719B-(6-Amino-2-naphthalenyl)boronic acid

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8003PentaneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

According to a known method described in a publication (Anderson, L. C. et al., J. Am. Chem. Soc, 1943, vol. 65, p. 241), a solution of 2-amino-6-bromonaphthalene (223 mg) obtainable from commercially available 2-bromo-6-hydroxynaphthalene (TCI) in anhydrous THF (10 ml) was added with 30% potassium hydride (191 mg, Ald) under ice cooling, and stirred for 1 hour. The reaction mixture was cooled to −78° C. under argon gas atmosphere, added dropwise with a 1.7 M solution of t-butyllithium in pentane (1.88 ml) over 10 minutes, and stirred for 30 minutes. This reaction mixture was added dropwise with (iPrO)3B (0.92 ml) over 10 minutes, stirred for 30 minutes, then warmed to room temperature, and further stirred for 3 hours. The reaction mixture was added with water (3 ml) and 0.5 M aqueous sulfuric acid (4 ml), and extracted with diethyl ether (100 ml×3). The organic layer was washed with saturated brine and dried, and then the solvent was evaporated under reduced pressure to obtain crude 6-amino-2-naphthaleneboronic acid (402 mg). A solution of this substance in ethanol (0.5 ml), Compound No. A-1 (119 mg), 2 M aqueous sodium carbonate (1.5 ml) and (Ph3P)4Pd (61 mg) were reacted and treated according to the procedure described in the synthesis method of Compound No. V-3 with the modifications that the reaction was carried out for 13 hours, and the purification was performed by flash column chromatography (hexane:ethyl acetate 4:1) to obtain the title compound (Compound No. V-13, 129 mg).

Workup

  1. stirringstirred for 30 minutes
  2. stirringstirred for 30 minutes
  3. temperaturewarmed to room temperature
  4. stirringfurther stirred for 3 hours
  5. extractionextracted with diethyl ether (100 ml×3)
  6. washThe organic layer was washed with saturated brine
  7. customdried
  8. customthe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-0f4a4bdb6e5544e9bca9c60c80e28824
Source dataset
uspto-grants-2008_12
Patent number
US07470807B2

Reaction notes

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