Hydrochloric Acid → 5-Nitro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzenemethanol

HRID 1425930Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([B:14]2[O:18][C:17]([CH3:20])([CH3:19])[C:16]([CH3:22])([CH3:21])[O:15]2)=[C:8]([CH:13]=1)[C:9](OC)=[O:10])([O-:3])=[O:2].[H-].C([Al+]CC(C)C)C(C)C.CO.Cl>C(Cl)Cl>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([B:14]2[O:18][C:17]([CH3:20])([CH3:19])[C:16]([CH3:22])([CH3:21])[O:15]2)=[C:8]([CH2:9][OH:10])[CH:13]=1)([O-:3])=[O:2]

Participants

Conditions

Temperature: 0 °C

Procedure

Methyl 5-nitro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate (C) (2.5 g, 8.14 mmol) was dissolved in DCM (25 mL), flushed with argon and cooled in an ice bath to 0° C. A solution of 1 M diisobutylaluminum hydride in DCM (20.5 mL, 20.35 mmol) was added dropwise so that the temperature remained below 3° C. over 2 h. The black reaction mixture was stirred at 0° C. for an additional 2 h. After this time, MeOH (3 mL) was added causing a yellow precipitate to form. 1 M aqueous HCl (50 mL) was then added and reaction was stirred for 30 min at 0° C. The layers were separated and the aqueous phase was extracted with EtOAc (3×50 mL). The combined organic phases were washed with brine and dried over anhydrous MgSO4 to produce (5-nitro-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)methanol (CI) as a black oil (1.25 g, 4.48 mmol, 55% yield, purity 85%). The product was used without further purification for step 3.

Workup

customflushed with argon
customThe black reaction mixture
customto form
customreaction
stirringwas stirred for 30 min at 0° C
customThe layers were separated
extractionthe aqueous phase was extracted with EtOAc (3×50 mL)
washThe combined organic phases were washed with brine
dry with materialdried over anhydrous MgSO4

Sources & evidence

ORD record: ord-455bd4d96c464fb3b5fa7a06d3307ba3
Source dataset: uspto-grants-2015_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08933018B2

Reaction notes

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