Réaction #65694

Équation de réaction

8-bromo-3,4-dihydro-1-benzothiepin-5(2H)-one

hydrazine hydrate

potassium hydroxide

→

8-bromo-2,3,4,5-tetrahydro-1-benzothiepine

Rendement 72.5%

Solvants

diethylene glycol

Conditions de réaction

Traitement

1. 1
   Températureheated to 180°-190° C.
2. 2
   Températureunder reflux for about 30 hours
3. 3
   TempératureAfter cooling
4. 4
   workup.ADDITIONthe mixture was poured on to ice
5. 5
   Extractionextracted with ether
6. 6
   LavageThe organic phase was washed with water
7. 7
   Autredried
8. 8
   Autreevaporated

Mode opératoire

15.6 g of 8-bromo-3,4-dihydro-1-benzothiepin-5(2H)-one were dissolved in 70 ml of diethylene glycol. The solution was treated with 6.55 ml of hydrazine hydrate and 7.5 g of solid potassium hydroxide and heated to 180°-190° C. under reflux for about 30 hours. After cooling, the mixture was poured on to ice and extracted with ether. The organic phase was washed with water, dried and evaporated. Chromatography on silica gel with petroleum ether yielded 10.7 g of 8-bromo-2,3,4,5-tetrahydro-1-benzothiepine as a colorless oil.

Source