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

HRID 1969349Notes

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 2.5 M 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 and acidified with 12N HCl to pH 3. The product was then extracted with ethyl acetate. The organic phase 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
extractionand the organic phase was extracted twice with water
extractionThe product was then extracted with ethyl acetate
customThe organic phase was dried
concentrationconcentrated under vacuum

Sources & evidence

ORD record: ord-b6abaf050e384662806df83e3c77870b
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08426591B2

Reaction notes

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