Sulfuric Acid → 9-Bromo-3,4,7,8-tetrahydro-[1,4]diazepino[7,1-a]isoquinoline-2,5-dione

HRID 532878Notes

Reaction equation

HRID 532878 reaction equation
BrC1C=CC=C2C=1CC[NH:6]C2CC(OC)=O.S(=O)(=O)(O)O.[C:22]([N:25]1[CH2:34][CH2:33][C:32]2[C:27](=[CH:28][CH:29]=[CH:30][C:31]=2[Br:35])[CH:26]1[CH2:36][C:37]([O:39]C)=O)(=[O:24])[CH3:23].C([O-])(O)=O.[Na+]>O.CO>[Br:35][C:31]1[CH:30]=[CH:29][CH:28]=[C:27]2[C:32]=1[CH2:33][CH2:34][N:25]1[C:22](=[O:24])[CH2:23][NH:6][C:37](=[O:39])[CH:36]=[C:26]12

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 86711329Methyl 2-(5-bromo-1,2,3,4-tetrahydroisoquinolin-1-yl)acetateHCID 89980026Methyl 2-(2-acetyl-5-bromo-1,2,3,4-tetrahydroisoquinolin-1-yl)acetate

Product 1

HCID 867113289-Bromo-3,4,7,8-tetrahydro-[1,4]diazepino[7,1-a]isoquinoline-2,5-dione

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

methyl 2-(5-bromo-1,2,3,4-tetrahydroisoquinolin-1-yl)acetate. MeOH (1280 mL) was cooled to −15° C. and conc. Sulfuric acid (147 mL, 2759 mmol) was added slowly (exotherm) under cooling. To this solution, methyl 2-(2-acetyl-5-bromo-1,2,3,4-tetrahydroisoquinolin-1-yl)acetate (90 g, 276 mmol) was added and the reaction mixture was stirred under reflux for 96 h. The reaction mixture was cooled to RT and slowly added to a solution of NaHCO3 (540 g) in water (1.35 L). The slightly basic aqueous solution was extracted with AcOEt (3×500 mL). The combined organic layers were washed with saturated aqueous NaHCO3 (300 mL) and brine (300 mL). The organic layer was dried with sodium sulfate, filtered and the solvent was removed under reduced pressure. The crude product was dried under high vacuo to yield the title compound as yellow foam (76 g) which was used without further purification. UPLC-MS: MS 284.1/286.1 (M+H+); UPLC rt 0.50 min.

Workup

  1. temperatureunder cooling
  2. temperatureunder reflux for 96 h
  3. extractionThe slightly basic aqueous solution was extracted with AcOEt (3×500 mL)
  4. washThe combined organic layers were washed with saturated aqueous NaHCO3 (300 mL) and brine (300 mL)
  5. dry with materialThe organic layer was dried with sodium sulfate
  6. filtrationfiltered
  7. customthe solvent was removed under reduced pressure
  8. dry with materialThe crude product was dried under high vacuo

Sources & evidence

ORD record
ord-2b19f0609ed54cb48b01ca0f92017582
Source dataset
uspto-grants-2014_10
Patent number
US08853203B2

Reaction notes

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