Dimethyl Disulfide → 1-Bromo-4-chloro-3-methylthio-2-fluorobenzene

HRID 1496880Notes

Reaction equation

HRID 1496880 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[F:9].[Li+].CC([N-]C(C)C)C.[CH3:18][S:19]SC>C1COCC1>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[C:4]([S:19][CH3:18])[C:3]=1[F:9]

Participants

5

Conditions

Temperature
-20 °C

Procedure

A solution of 1-bromo-4-chloro-2-fluorobenzene (20.4 g, 0.100 mol) in THF (50 mL) was slowly added to LDA (0.125 mol) in THF (600 mL) at −50° C. After addition, the solution was warmed to −20° C. and then cooled to −50° C. A solution of dimethyldisulfide (18.8 g, 0.20 mol) in THF (50 mL) was then slowly added and the mixture was warmed to ambient temperature. The reaction was quenched with water (200 mL), extracted with ethyl acetate (2×150 mL), and the combined organic phases dried and concentrated. The residual red oil was purified by chromatography (5% ethyl acetate in hexanes) to give 1-bromo-4-chloro-3-methylthio-2-fluorobenzene (23.9 g, 0.094 mol): 1H NMR (CDCl3): δ 7.40 (m, 1H), 7.15 (dd, 1H), 2.50 (s, 3H).

Workup

  1. additionAfter addition
  2. temperaturecooled to −50° C
  3. temperaturethe mixture was warmed to ambient temperature
  4. customThe reaction was quenched with water (200 mL)
  5. extractionextracted with ethyl acetate (2×150 mL)
  6. customthe combined organic phases dried
  7. concentrationconcentrated
  8. customThe residual red oil was purified by chromatography (5% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-b39bcf1b529447eabcd8bae08b7afecf
Source dataset
uspto-grants-2015_12
Patent number
US09199943B2

Reaction notes

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