Reaction #1702081

Reaction equation

Sodium perborate tetrahydrate

KBr

5-cyclopropyl-2,3,5,6-tetrahydrobenzo[b][1,5]diazocin-4(1H)-one

→

desired product

Yield 45.4%

8-bromo-5-cyclopropyl-2,3,5,6-tetrahydrobenzo[b][1,5]diazocin-4(1H)-one

Yield 45.4%

Solvents

acetic acid

Conditions

Workup

1. 1
   Otherquenched with sodium carbonate (aqueous saturated) and a few drops of NaOH (10% aqueous)
2. 2
   ExtractionThe mixture was extracted with ethyl acetate
3. 3
   Washthe combined organic phases were washed with sodium carbonate
4. 4
   Dryingdried over sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated
7. 7
   OtherPurification of the crude mixture by silica gel flash chromatography (0-20% methanol in ethyl acetate)

Procedure

Sodium perborate tetrahydrate (1.07 g, 6.94 mmol) was added in one portion to a suspension of KBr (0.770 g, 6.47 mmol), 5-cyclopropyl-2,3,5,6-tetrahydrobenzo[b][1,5]diazocin-4(1H)-one (1.00 g, 4.62 mmol) and ammonium molybdate tetrahydrate (0.114 mg, 0.092 mmol) in acetic acid (10 ml). The mixture was stirred at room temperature for 24 hours, then quenched with sodium carbonate (aqueous saturated) and a few drops of NaOH (10% aqueous). The mixture was extracted with ethyl acetate and the combined organic phases were washed with sodium carbonate, dried over sodium sulfate filtered and concentrated. Purification of the crude mixture by silica gel flash chromatography (0-20% methanol in ethyl acetate) gave the desired product as a brown solid (0.619 g, 45%).

Source