Reaktion #72544

Reaktionsgleichung

HCl

ethyl(methylsulphanyl)acetate

ethyl 4-amino-benzoate

tBuOCl

→

title product

Ethyl 3-methylsulphanyl-2-oxo-2,3-dihydro-1H-indole-5-carboxylate

Lösungsmittel

ether

triethylamine

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturmaintaining the temperature between −60° C. and −55° C
2. 2
   Sonstigeis brought to 0° C.
3. 3
   workup.STIRRINGAfter stirring for 12 hours at ambient temperature
4. 4
   Sonstigethe phases are separated
5. 5
   Waschenthe organic phase is washed successively with aq. 2M HCl solution, water
6. 6
   TrocknenThe organic phase is dried over sodium sulphate
7. 7
   Filtrationfiltered
8. 8
   Sonstigeevaporated to dryness
9. 9
   SonstigeThe residue obtained
10. 10
    SonstigeThe crystals obtained
11. 11
    Filtrationare filtered off
12. 12
    Waschenwashed with ether
13. 13
    Sonstigedried in vacuo

Vorschrift

To a solution of ethyl 4-amino-benzoate (40.0 g) in DCM (900 ml) at −60° C. there is added, dropwise, ethyl(methylsulphanyl)acetate (34.5 ml) under a nitrogen atmosphere. 29.0 g of tBuOCl are then added, dropwise, to the reaction mixture over 25 minutes, maintaining the temperature between −60° C. and −55° C. After stirring for one hour at −50° C., triethylamine (15.4 ml) is added dropwise. The reaction mixture is brought to 0° C. and then aqueous 3M HCl solution (485 ml) is added dropwise. After stirring for 12 hours at ambient temperature, the phases are separated and the organic phase is washed successively with aq. 2M HCl solution, water and then sat. aqueous NaCl solution. The organic phase is dried over sodium sulphate, filtered and evaporated to dryness. The residue obtained is taken up in ether. The crystals obtained are filtered off, washed with ether and dried in vacuo to yield the title product, which is used directly in the next Step.

Quelle