Réaction #46392

Équation de réaction

sulphuric acid

N-(1,1-dioxo-2,3-dihydro-1H-1λ6-benzo[b]thiophen-5-yl)-2-[(E)-hydroxyimino]acetamide

→

desired compound

Rendement 52.5%

3,3-dioxo-1,2,3,6-tetrahydro-3λ6-thieno[3,2-e]indole-7,8-dione

Rendement 52.5%

Solvants

ethyl acetate

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter the addition
2. 2
   Températurethe reaction mixture was heated to 90° C.
3. 3
   Températureto cool to RT
4. 4
   workup.STIRRINGbriefly stirred
5. 5
   AutreAfter separation of the phases
6. 6
   Autrethe solid which formed
7. 7
   Filtrationwas filtered off with suction
8. 8
   Lavagewashed with diethyl ether
9. 9
   Autredried in a drying oven at 50° C. overnight

Mode opératoire

6.74 ml (126.38 mmol) of conc. sulphuric acid were introduced into a three-neck round-bottom flask with thermometer and high-efficiency condenser and heated to 70° C. 3.06 g (12.04 mmol) of N-(1,1-dioxo-2,3-dihydro-1H-1λ6-benzo[b]thiophen-5-yl)-2-[(E)-hydroxyimino]acetamide were then added in portions over the course of half an hour, during which the mixture became dark reddish brown in colour. After the addition was complete, the reaction mixture was heated to 90° C. and stirred at this temperature for one hour. For working up, the reaction mixture was allowed to cool to RT and was then added to a mixture of ice-water (110 ml) and ethyl acetate (25 ml) and briefly stirred. After separation of the phases, the solid which formed was filtered off with suction, washed with diethyl ether and dried in a drying oven at 50° C. overnight. 1.50 g of the desired compound were obtained.

Source