Water → 1,1-Dimethylethyl 4-(1,2,3,4-tetrahydro-5-isoquinolinyl)-1-piperazinecarboxylate

HRID 459831Notes

Reaction equation

HRID 459831 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:23]=[CH:22][CH:21]=[C:20]3[C:15]=2[CH:16]=[CH:17][N:18]=[CH:19]3)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].B.O>O1CCCC1>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][N:11]([C:14]2[CH:23]=[CH:22][CH:21]=[C:20]3[C:15]=2[CH2:16][CH2:17][NH:18][CH2:19]3)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

5

Reactant 3

HCID 962WaterHCID 6331BoraneHCID 21070949tert-Butyl 4-(isoquinolin-5-yl)piperazine-1-carboxylate

Product 1

HCID 210709471,1-Dimethylethyl 4-(1,2,3,4-tetrahydro-5-isoquinolinyl)-1-piperazinecarboxylateYield 44%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

4-Isoquinoline-5-yl-piperazine-1-carboxylic acid tert-butyl ester (1.5 g) from Step 2 was dissolved in 5 mL of tetrahydrofuran (THF), and excess borane (BH3) in THF was added thereto. The mixture was brought to reflux for 1 hour, and allowed to cool to room temperature. The mixture was then further cooled in an ice bath, and water was carefully added to the reaction mix to consume excess borane. The reaction mix was then diluted with EtOAc, washed with saturated aqueous sodium bicarbonate (NaHCO3), dried over MgSO4, and chromatographed to provide 4-(1,2,3,4-tetrahydroisoquinolin-5-yl)-piperazine-1-carboxylic acid tert-butyl ester as a viscous oil (0.668 g).

Workup

  1. temperatureto reflux for 1 hour
  2. temperatureThe mixture was then further cooled in an ice bath
  3. additionmix
  4. customto consume excess borane
  5. additionThe reaction mix
  6. additionwas then diluted with EtOAc
  7. washwashed with saturated aqueous sodium bicarbonate (NaHCO3)
  8. dry with materialdried over MgSO4
  9. customchromatographed

Sources & evidence

ORD record
ord-088f496a429b4e08a3dc00dd593b586d
Source dataset
uspto-grants-2007_03
Patent number
US07196088B2

Reaction notes

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