1-Chloro-2,3-difluorobenzene → 2-(4-Chloro-2,3-difluorophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

HRID 2386122Notes

Reaction equation

C([Li])CCC.[Cl:6][C:7]1[CH:12]=[CH:11][CH:10]=[C:9]([F:13])[C:8]=1[F:14].C(O[B:19]1[O:23][C:22]([CH3:25])([CH3:24])[C:21]([CH3:27])([CH3:26])[O:20]1)(C)C>C1COCC1.O.C(OCC)(=O)C>[Cl:6][C:7]1[CH:12]=[CH:11][C:10]([B:19]2[O:23][C:22]([CH3:25])([CH3:24])[C:21]([CH3:27])([CH3:26])[O:20]2)=[C:9]([F:13])[C:8]=1[F:14]

Participants

Conditions

Temperature: -78 °C

Procedure

A 2.5M solution of n-butyllithium (2.69 ml, 6.73 mmol) in hexanes was added dropwise to a solution of 1-chloro-2,3-difluorobenzene (1 g, 6.73 mmol) in THF (25 mL) cooled to −78° C. After 45 min at −78° C., 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.253 g, 6.73 mmol) was added dropwise after which the reaction mixture was allowed to warm to ambient temperature. The reaction mixture was diluted with water and ethyl acetate, and the organic phase was extracted twice with water. The aqueous extracts were combined, acidified with 12N HCl to pH 3, and extracted with ethyl acetate. The organic extract was dried and concentrated under vacuum to yield the title compound as an oil product (0.93 g, 50% yield): 1H NMR (CDCl3) δ 7.42 (m, 1H), 7.17 (m, 1H), 1.37 (s, 12H).

Workup

temperatureto warm to ambient temperature
extractionthe organic phase was extracted twice with water
extractionextracted with ethyl acetate
extractionThe organic extract
customwas dried
concentrationconcentrated under vacuum

Sources & evidence

ORD record: ord-4094bd2c114f42ed966fecdecb4638c0
Source dataset: uspto-grants-2012_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08268753B2

Reaction notes

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