Reaktion #75925

Reaktionsgleichung

5-(chloromethyl)-1,3-difluoro-2-(methylthio)benzene

lithium bromide

acetone

lithium bromide

sodium bromide

→

5-(bromomethyl)-1,3-difluoro-2-(methylthio)benzene

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturat reflux for 18 hours
3. 3
   Extraktionextracted with dichloromethane (1×200 mL, 2×50 mL)
4. 4
   SonstigeThe combined extracts were dried
5. 5
   Einengenconcentrated
6. 6
   workup.DISSOLUTIONThe residue was dissolved in acetone (200 mL)
7. 7
   Temperaturthe mixture heated
8. 8
   Temperaturat reflux for 42 hours
9. 9
   TemperaturThe mixture was cooled
10. 10
    Extraktionextracted with dichloromethane (1×150 mL, 1×50 mL)
11. 11
    WaschenThe combined extracts were washed with dilute sodium chloride
12. 12
    Trocknendried with magnesium sulfate
13. 13
    Einengenconcentrated
14. 14
    SonstigeThe 5-(bromomethyl)-1,3-difluoro-2-(methylthio)benzene was purified

Vorschrift

A mixture of 5-(chloromethyl)-1,3-difluoro-2-(methylthio)benzene (21.3 g, 0.10 mol), lithium bromide (15 g, 0.17 mol), and acetone (200 mL) was heated and held at reflux for 18 hours. The cool mixture was poured into water and extracted with dichloromethane (1×200 mL, 2×50 mL). The combined extracts were dried using magnesium sulfate, and concentrated. The residue was dissolved in acetone (200 mL), lithium bromide (30 g, 0.34 mol) and sodium bromide (20 g, 0.19 mol) were added and the mixture heated and held at reflux for 42 hours. The mixture was cooled, added to water, and extracted with dichloromethane (1×150 mL, 1×50 mL). The combined extracts were washed with dilute sodium chloride, dried with magnesium sulfate, and concentrated. The 5-(bromomethyl)-1,3-difluoro-2-(methylthio)benzene was purified using silica gel chromatography using hexanes as a yellow solid (20.5 g, 80%). 1H NMR (CDCl3/400 MHz) 6.92-6.95 (m, 2H), 4.37 (s, 2H), 2.45 (s, 3H). HRMS m/z 251.9432 (M+, calcd 251.9420).

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