Citric Acid → tert-butyl 6-[2-(benzoylamino)ethyl]-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate

HRID 2306964Notes

Reaction equation

HRID 2306964 reaction equation
[NH2:1][CH2:2][CH2:3][N:4]1[C:12]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[C:6]2[CH2:13][CH2:14][N:15]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:16][CH2:17][C:5]1=2.C(N(C(C)C)CC)(C)C.[C:34](Cl)(=[O:41])[C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1>[C:34]([NH:1][CH2:2][CH2:3][N:4]1[C:12]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[C:6]2[CH2:13][CH2:14][N:15]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:16][CH2:17][C:5]1=2)(=[O:41])[C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1

Participants

6

Reactant 4

HCID 311Citric AcidHCID 7412Benzoyl chlorideHCID 81531DiisopropylethylamineHCID 22396663tert-butyl 6-(2-aminoethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate

Product 1

HCID 22396732tert-butyl 6-[2-(benzoylamino)ethyl]-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylateYield 75.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

tert-Butyl 6-(2-aminoethyl)-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (0.0401 g, 0.122 mmol) was dissolved in THF (2 mL) at rt under N2. Diisopropylethylamine (0.028 mL, 0.0205 g, 0.158 mmol, 1.30 equiv.) and benzoyl chloride (0.017 mL, 0.0205 g, 0.146 mmol, 1.20 equiv.) were added, then the reaction mixture was stirred for 19 h. Citric acid (10%) was added and the reaction mixture was stirred for 15 min. The reaction mixture was extracted with EtOAc and the organic layer was washed sequentially with 10% citric acid, saturated aqueous NaHCO3, and brine. The organic layer was dried over MgSO4, filtered and concentrated. The crude product (0.056 g) was chromatographed (SiO2 25 g, eluted with 1:1 hexane:EtOAc) to give tert-butyl 6-[2-(benzoylamino)ethyl]-1,4,5,6-tetrahydroazepino[4,5-b]indole-3(2H)-carboxylate (0.0398 g) in 75% yield. 1H NMR (300 MHz, CDCl3) δ 1.45, 1.48, 2.96-3.05, 3.60-3.70, 3.74, 4.36-4.42, 6.29, 7.10-7.19, 7.31-7.43, 7.46-7.53, 7.63; MS (ESI+) for C26H31N3O3 m/z 434.1 (M+H)+.

Workup

  1. stirringthe reaction mixture was stirred for 15 min
  2. extractionThe reaction mixture was extracted with EtOAc
  3. washthe organic layer was washed sequentially with 10% citric acid, saturated aqueous NaHCO3, and brine
  4. dry with materialThe organic layer was dried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe crude product (0.056 g) was chromatographed
  8. wash(SiO2 25 g, eluted with 1:1 hexane:EtOAc)

Sources & evidence

ORD record
ord-1faa67de3ef140a390d9da316c58c86a
Source dataset
uspto-grants-2004_12
Patent number
US06828314B2

Reaction notes

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