1-Piperazinecarboxylic acid, ethyl ester → 9-Bromo-6-(4-ethoxycarbonyl-1-piperazinyl)-1,2-dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine

HRID 35115

Reaction equation

HRID 35115 reaction equation
[Br:1][C:2]1[CH:19]=[CH:18][C:5]2[N:6]3[CH2:17][CH2:16][C:15]4[C:7]3=[C:8]([CH:12]=[CH:13][CH:14]=4)[C:9](=O)[NH:10][C:4]=2[CH:3]=1.[CH3:20][CH2:21][O:22][C:23]([N:25]1[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]1)=[O:24].[OH-].[Na+]>[Ti](Cl)(Cl)(Cl)Cl.C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:19]=[CH:18][C:5]2[N:6]3[CH2:17][CH2:16][C:15]4[C:7]3=[C:8]([CH:12]=[CH:13][CH:14]=4)[C:9]([N:28]3[CH2:27][CH2:26][N:25]([C:23]([O:22][CH2:21][CH3:20])=[O:24])[CH2:30][CH2:29]3)=[N:10][C:4]=2[CH:3]=1

Participants

6

Reactant 3

HCID 84311-Piperazinecarboxylic acid, ethyl esterHCID 14798Sodium HydroxideHCID 138232839-Bromo-1,2dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine-6-one

Product 1

HCID 138232999-Bromo-6-(4-ethoxycarbonyl-1-piperazinyl)-1,2-dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine

Reagents, catalysts & solvents 2

HCID 24193Titanium TetrachlorideCatalystHCID 1140TolueneSolvent

Procedure

A stirred mixture of 7.88 g (0.025 mole) of 9-bromo-1,2dihydrobenzo[b]pyrrolo[3,2,1-jk][1,4]benzodiazepine-6-one and 1200 ml toluene was heated under nitrogen until a solution resulted. Then there was added 39.6 g (0.250 mole) of ethyl N-piperazinocarboxylate followed by 14.2 g (0.075 mole) of titanium tetrachloride. The mixture was heated under reflux for three hours, cooled to room temperature and treated with 500 ml of 2N sodium hydroxide solution. After stirring vigorously for 15 minutes, the layers were separated. The aqueous phase was extracted with 300 ml of toluene. The toluene layers were combined, washed once with 2N sodium hydroxide solution, twice with water, dried over anhydrous sodium sulfate, and concentrated in vacuo. The residue was taken up in 25 ml of hot methanol from which 8.5 g (75%) of product crystallized. Recrystallization from ethyl acetate gave the analytical sample, mp 128°-131° C.

Workup

  1. temperaturewas heated under nitrogen until a solution
  2. customresulted
  3. temperatureThe mixture was heated
  4. temperatureunder reflux for three hours
  5. customthe layers were separated
  6. extractionThe aqueous phase was extracted with 300 ml of toluene
  7. washwashed once with 2N sodium hydroxide solution, twice with water
  8. dry with materialdried over anhydrous sodium sulfate
  9. concentrationconcentrated in vacuo
  10. customcrystallized
  11. customRecrystallization from ethyl acetate
  12. customgave the analytical sample, mp 128°-131° C.

Sources & evidence

ORD record
ord-b31840e534124f6c8d62d168a7c20e41
Source dataset
uspto-grants-1988_08
Patent number
US04764616

Linked notes

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