Borane → 2-[3-(2-ethylamino-ethylamino)-propyl]-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester

HRID 2191504Notes

Reaction equation

HRID 2191504 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH3:11])=[CH:9][NH:8][C:7]=1[CH2:12][CH2:13][C:14](=O)[NH:15][CH2:16][CH2:17][NH:18][C:19](=O)[CH3:20])=[O:5])[CH3:2].B>O1CCCC1>[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH3:11])=[CH:9][NH:8][C:7]=1[CH2:12][CH2:13][CH2:14][NH:15][CH2:16][CH2:17][NH:18][CH2:19][CH3:20])=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 6331BoraneHCID 592500792-[2-(2-acetylamino-ethylcarbamoyl)-ethyl]-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester

Product 1

HCID 592500552-[3-(2-ethylamino-ethylamino)-propyl]-4-methyl-1H-pyrrole-3-carboxylic acid ethyl esterYield 31.1%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

2-[2-Acetylamino-ethylcarbamoyl)-ethyl]-4-methyl-1H-pyrrole-3-carboxyl is acid ethyl ester 62b (600 mg, 1.94 mmol) was dissolved in 4 ml of tetrahydrofuran under stirring, and added with a solution of borane in tetrahydrofuran (7.79 ml, 1 mol/L, 7.79 mmol) to the solution in an ice-water bath under an argon atmosphere. Upon completion of the addition, the reaction mixture was heated to reflux for 2 hours. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was quenched with hydrochloric acid, stirred for 30 minutes at room temperature, adjusted to about pH 12 with aqueous sodium hydroxide solution (10%) and extracted with ethyl acetate (30 ml×3). The combined organic extracts were washed with saturated brine (30 ml), dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound 2-[3-(2-ethylamino-ethylamino)-propyl]-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester 62c (170 mg, yield 31%) as a white solid.

Workup

  1. additionUpon completion of the addition
  2. temperaturethe reaction mixture was heated
  3. temperatureto reflux for 2 hours
  4. customthe reaction mixture was quenched with hydrochloric acid
  5. stirringstirred for 30 minutes at room temperature
  6. extractionextracted with ethyl acetate (30 ml×3)
  7. washThe combined organic extracts were washed with saturated brine (30 ml)
  8. dry with materialdried over anhydrous magnesium sulfate
  9. filtrationfiltered
  10. customto remove the drying agent
  11. concentrationconcentrated under reduced pressure
  12. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-c2ca24058eca4240a4f836776f5ac5bb
Source dataset
uspto-grants-2012_12
Patent number
US08329682B2

Reaction notes

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