Reaction #4165

Reaction equation

N-propylpiperazine

9-bromo-1,2-dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepin-6-one

sodium hydroxide

→

product

Yield 30.1%

9-Bromo-6-(4-n-propyl-1-piperazinyl)-1,2-dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine

Yield 30.1%

Solvents

toluene

Conditions

Workup

1. 1
   Temperaturewas heated until a solution
2. 2
   Otherresulted
3. 3
   TemperatureThe mixture was refluxed for 3 hours
4. 4
   Otherthe layers were separated
5. 5
   ExtractionThe aqueous phase was extracted with 300 ml of toluene
6. 6
   Filtrationfiltered
7. 7
   Washwashed once with 2N sodium hydroxide solution, twice with water
8. 8
   Dryingdried over anhydrous sodium sulfate
9. 9
   Concentrationconcentrated to an oily solid
10. 10
    workup.DISSOLUTIONThe oily solid was dissolved in 25 ml of hot ethyl acetate
11. 11
    Filtrationfiltered
12. 12
    Otherto crystallize first at room temperature

Procedure

A stirred mixture of 7.88 g (0.0250 mole) of 9-bromo-1,2-dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepin-6-one and 1200 ml of toluene was heated until a solution resulted. Then there was added 32.1 g (0.25 mole) of N-propylpiperazine, followed by 14.2 g (0.075 mole) of titanium tetrachloride. The mixture was refluxed for 3 hours, and then cooled to room temperature. The mixture was stirred with 500 ml of 2N sodium hydroxide solution for 15 minutes and the layers were separated. The aqueous phase was extracted with 300 ml of toluene. The toluene layers were combined, filtered, washed once with 2N sodium hydroxide solution, twice with water, dried over anhydrous sodium sulfate, and concentrated to an oily solid. The oily solid was dissolved in 25 ml of hot ethyl acetate, filtered, and allowed to crystallize first at room temperature, then at 0° C. to yield 3.20 g (30%) of product, mp 134°-136° C.

Source