Triethylamine → 2-Amino-4-chlorophenylboronic acid pinacol ester

HRID 1012231Notes

Reaction equation

Br[C:2]1[CH:8]=[CH:7][C:6]([Cl:9])=[CH:5][C:3]=1[NH2:4].C(N(CC)CC)C.[CH3:17][C:18]1([CH3:25])[C:22]([CH3:24])([CH3:23])[O:21][BH:20][O:19]1>O1CCOCC1>[Cl:9][C:6]1[CH:7]=[CH:8][C:2]([B:20]2[O:21][C:22]([CH3:24])([CH3:23])[C:18]([CH3:25])([CH3:17])[O:19]2)=[C:3]([NH2:4])[CH:5]=1

Participants

Conditions

Temperature: 100 °C

Procedure

To a solution of 2-bromo-5-chloroaniline (20.0 g, 96.9 mmol) in 1,4-dioxane (200 ml) were added triethylamine (54.0 ml, 487 mmol) and [1,1-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane complex (3.96 g, 4.84 mmol), and under a nitrogen stream, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (42.3 ml, 290 mmol) was added dropwise. The mixture was stirred at 100° C. for 10.5 hr. The mixture was allowed to cool to room temperature and filtered through celite. To the filtrate was added dropwise methanol (25 ml) at 0° C. The solvent was evaporated under reduced pressure, and the obtained residue was purified by silica gel chromatography (hexane:ethyl acetate=20:1) to give 5-chloro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenylamine (16.5 g, yield. 65%).

Workup

temperatureto cool to room temperature
filtrationfiltered through celite
additionTo the filtrate was added dropwise methanol (25 ml) at 0° C
customThe solvent was evaporated under reduced pressure
customthe obtained residue was purified by silica gel chromatography (hexane:ethyl acetate=20:1)

Sources & evidence

ORD record: ord-2c06441eb6154cab8b5b1e309bf8e7b9
Source dataset: uspto-grants-2011_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07977331B1

Reaction notes

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