Reaktion #475405

Reaktionsgleichung

1-chloroethylchloroformate

2-benzyl-4-bromoisoindoline hydrochloride

NaOH

→

title compound

Ausbeute 111.5%

4-Bromoisoindoline

Ausbeute 111.5%

Lösungsmittel

EtOAc

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe organic layer was separated
2. 2
   Waschenwashed with brine
3. 3
   Trocknendried over anhydrous Na2SO4 and solvent
4. 4
   Sonstigeevaporated to an oil which
5. 5
   Sonstigewas azeotroped once with PhMe (50 mL)
6. 6
   workup.DISSOLUTIONThe oil was dissolved in chlorobenzene (50 mL)
7. 7
   workup.ADDITION4A molecular sieves (5 g) added to the stirred solution
8. 8
   workup.WAITAfter 10 minutes
9. 9
   Temperaturcooled to RT
10. 10
    Filtrationfiltered
11. 11
    WaschenThe solids were washed with chlorobenzene (5 mL) and MeOH (40 mL)
12. 12
    TemperaturThe filtrate was heated to 70° C. for 1 hour
13. 13
    Temperaturto cool
14. 14
    workup.STIRRINGstirred at RT overnight
15. 15
    FiltrationThe solids were filtered
16. 16
    Waschenwashed with chlorobenzene (2 mL) and hexane
17. 17
    Sonstigedried

Vorschrift

To a solution of 2-benzyl-4-bromoisoindoline hydrochloride (11 g, 30.96 mmol) in 200 mL EtOAc was added 1M NaOH (100 mL) and the mixture stirred for 30 minutes. The organic layer was separated, washed with brine, dried over anhydrous Na2SO4 and solvent evaporated to an oil which was azeotroped once with PhMe (50 mL). The oil was dissolved in chlorobenzene (50 mL) and 4A molecular sieves (5 g) added to the stirred solution. After 10 minutes, 1-chloroethylchloroformate (5.6 mL, 51 mmol) was added dropwise over 5 minutes. The reaction mixture was then heated to 90° C. for 2 hours, cooled to RT and filtered. The solids were washed with chlorobenzene (5 mL) and MeOH (40 mL). The filtrate was heated to 70° C. for 1 hour, allowed to cool and stirred at RT overnight. The solids were filtered, washed with chlorobenzene (2 mL) and hexane and dried to give 6.84 g of title compound. LRMS (ESI) m/z 198.1 [(M+H)+; calcd for C8H9BrN: 198.0].

Quelle