1-Isopropylpiperazine → 5-(4-Isopropyl-piperazine-1-carbonyl)-1H-indole-2-carboxylic acid ethyl ester

HRID 1820320Notes

Reaction equation

HRID 1820320 reaction equation
[CH3:1][CH2:2][O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([OH:17])=O)=[CH:10][CH:9]=2)=[O:5].F[B-](F)(F)F.N1(OC(N(C)C)=[N+](C)C)C2C=CC=CC=2N=N1.[CH:40]([N:43]1[CH2:48][CH2:47][NH:46][CH2:45][CH2:44]1)([CH3:42])[CH3:41].C(N(CC)C(C)C)(C)C.C(=O)(O)[O-].[Na+]>CN(C)C=O>[CH2:2]([O:3][C:4]([C:6]1[NH:7][C:8]2[C:13]([CH:14]=1)=[CH:12][C:11]([C:15]([N:46]1[CH2:47][CH2:48][N:43]([CH:40]([CH3:42])[CH3:41])[CH2:44][CH2:45]1)=[O:17])=[CH:10][CH:9]=2)=[O:5])[CH3:1]

Participants

7

Reactant 5

HCID 780131-IsopropylpiperazineHCID 81531DiisopropylethylamineHCID 516892Sodium BicarbonateHCID 2733207O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborateHCID 180713652-(Ethoxycarbonyl)-1H-indole-5-carboxylic acid

Product 1

HCID 685341345-(4-Isopropyl-piperazine-1-carbonyl)-1H-indole-2-carboxylic acid ethyl esterYield 74.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To the solution of 5.0 g (21.4 mmol) 1H-indole-2,5-dicarboxylic acid 2-ethyl ester (prepared according to J. Org. Chem. 1953, 18, 345-57) in 50 mL N,N-dimethylformamide, 8.6 g (26.8 mmol) O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (commercially available) were added. After 10 min., 3.44 g (26.8 mmol) 1-isopropylpiperazine (commercially available) and 18.3 mL (13.9 g, 107.4 mmol) N,N-diisopropylethylamine were added. After 45 min. the reaction mixture was poured on saturated aqueous sodium bicarbonate solution and was extracted three times with ethyl acetate. The combined organic layers were washed three times with water followed by brine, dried over magnesium sulfate, filtered and evaporated. The residue was flash-chromatographed on silica gel with dichloromethane:methanol:ammonia (9:1:0.1 v/v) and ethyl acetate: methanol (9:1) as eluant to give 5.5 g (74%) of the desired compound as a light yellow solid.

Workup

  1. extractionwas extracted three times with ethyl acetate
  2. washThe combined organic layers were washed three times with water
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customThe residue was flash-chromatographed on silica gel with dichloromethane:methanol:ammonia (9:1:0.1 v/v) and ethyl acetate: methanol (9:1) as eluant

Sources & evidence

ORD record
ord-0d7a74ae3a844ad3a28d17760888ea7c
Source dataset
uspto-grants-2009_10
Patent number
US07601711B2

Reaction notes

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