Reaction #1830

Reaction equation

2,3,4,5-tetrahydro-1H-1-benzazepin-2-one

sodium sulfite

sodium sulfite

hexamethyldisilazane

iodine

→

product

Yield 57.5%

3-Iodo-2,3,4,5-tetrahydro-1H-1-benzazepin-2-one

Yield 57.5%

Solvents

water

methylene chloride

Conditions

Workup

1. 1
   Temperaturewas heated
2. 2
   Temperatureat reflux for 10 minutes
3. 3
   TemperatureThe mixture was heated
4. 4
   Temperatureat reflux for 2.5 hours
5. 5
   Temperaturethen cooled to room temperature
6. 6
   workup.ADDITIONwas poured the reaction mixture in several portions
7. 7
   Temperaturewhile maintaining the temperature below 10° C
8. 8
   WashThe reaction vessel was rinsed with 22.33 L of methylene chloride
9. 9
   workup.STIRRINGThe quenching mixture was stirred vigorously
10. 10
    Otherto separate
11. 11
    OtherThe aqueous layer was removed
12. 12
    WashThe combined organic layers were washed with 11 L of water
13. 13
    Concentrationconcentrated under vacuum to a final volume of approximately 5 L
14. 14
    workup.ADDITIONThe residue was treated with 55 L of toluene
15. 15
    Concentrationconcentrated under vacuum to a final volume of 10 L
16. 16
    OtherThe resulting slurry was removed by filtration
17. 17
    Washthe filter cake washed with an additional 5 L of toluene
18. 18
    Otherdried under vacuum at ambient temperature for 24 hours

Procedure

A suspension of 1.8 Kg (11.17 mol) of 2,3,4,5-tetrahydro-1H-1-benzazepin-2-one in a mixture of 22.33 L of methylene chloride and 11.78 L (55.83 mol) of hexamethyldisilazane was heated at reflux for 10 minutes then cooled to 30° C. and treated with 8.503 Kg (33.5 mol) of iodine in one portion. The mixture was heated at reflux for 2.5 hours then cooled to room temperature. Aqueous sodium sulfite containing 4.926 Kg of sodium sulfite in 44 L of water was cooled to 0° C. and into it was poured the reaction mixture in several portions with vigorous stirring while maintaining the temperature below 10° C. The reaction vessel was rinsed with 22.33 L of methylene chloride and the washing transferred to the quenching mixture. The quenching mixture was stirred vigorously and the layers allowed to separate. The aqueous layer was removed and reextracted with 22.33 L of methylene chloride. The combined organic layers were washed with 11 L of water and concentrated under vacuum to a final volume of approximately 5 L. The residue was treated with 55 L of toluene and concentrated under vacuum to a final volume of 10 L. The resulting slurry was removed by filtration and the filter cake washed with an additional 5 L of toluene and dried under vacuum at ambient temperature for 24 hours to give 1.842 Kg (6.42 mol, 57%) of product. 1H NMR (200 MHz,CDCl3): 2.6-2.8 (m,3H), 2.93 (m,1H), 4.64 (t,8 Hz,1H), 6.97 (d,8 Hz,1H), 7.10-7.35 (m,3H), 7.55 (br s,1H).

Source