1,2-Dibromo-1,1,2,2-tetrafluoroethane → HCID 9970540, compound

HRID 1611482Notes

Reaction equation

[Cl:1][C:2]1[C:7]([C:8]#[N:9])=[CH:6][N:5]=[C:4]2[CH:10]=[CH:11][S:12][C:3]=12.C(NC(C)C)(C)C.[Li].[Br:21]C(F)(F)C(Br)(F)F>O1CCCC1>[Br:21][C:11]1[S:12][C:3]2[C:4](=[N:5][CH:6]=[C:7]([C:8]#[N:9])[C:2]=2[Cl:1])[CH:10]=1

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of 7-chlorothieno[3,2-b]pyridine-6-carbonitrile (200 mg, 1.03 mmol) in tetrahydrofuran (5.0 mL) is slowly added lithium diisopropylamine (0.7 mL, 1.40 mmol, 2M in tetrahydrofuran) at −78° C. over 5 minutes. After 30 minutes, 1,2-dibromo-1,1,2,2-tetrafluoroethane (0.16 mL, 1.3 mmol) is added slowly to the solution of the anion. The temperature is maintained at −78° C. for 4 hours then warmed to room temperature for 1 hour. The reaction mixture is poured into ice water, extracted with dichloromethane, dried over sodium sulfate, and concentrated in vacuo to afford a dark solid residue. The residue is purified by flash column chromatography eluting with a gradient of 2% ethyl acetate in hexane to 8% ethyl acetate in hexane to provide 103 mg of 2-bromo-7-chlorothieno[3,2-b]pyridine-6-carbonitrile as an off white solid, mp 190-191° C.; 1H NMR (DMSO-d6) δ 8.13 (s, 1H), 9.12 (s, 1H); MS 272.8, 274.8, 276.9 (M+H)+.

Workup

customat −78° C.
customover 5 minutes
temperaturethen warmed to room temperature for 1 hour
extractionextracted with dichloromethane
dry with materialdried over sodium sulfate
concentrationconcentrated in vacuo
customto afford a dark solid residue
customThe residue is purified by flash column chromatography
washeluting with a gradient of 2% ethyl acetate in hexane to 8% ethyl acetate in hexane

Sources & evidence

ORD record: ord-77a296b3ecde48558af2c65c2955d1dc
Source dataset: uspto-grants-2006_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06987116B2

Reaction notes

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