6-Aminohexanoic Acid → 6-Maleimidohexanoic acid

HRID 1086410Notes

Reaction equation

HRID 1086410 reaction equation
[NH2:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([OH:9])=[O:8].C(N1[C:18](=[O:19])[CH:17]=[CH:16][C:15]1=[O:20])(OC)=O.S(=O)(=O)(O)O>C(=O)(O)[O-].[Na+].O>[CH:16]1[C:15](=[O:20])[N:1]([CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([OH:9])=[O:8])[C:18](=[O:19])[CH:17]=1

Participants

6

Reactant 3

HCID 5646-Aminohexanoic AcidHCID 1118Sulfuric AcidHCID 580610N-(Methoxycarbonyl)maleimide

Product 1

HCID 5736836-Maleimidohexanoic acidYield 68.9%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 516892Sodium BicarbonateSolvent

Procedure

A solution of 4.2 g (32.3 mmol) of 6-aminocaproic acid in 163 ml of saturated sodium bicarbonate solution is treated at 0° C., with vigorous stirring, with 5 g (32.3 mmol) of N-carbomethoxymaleimide. After 1 hour, the solution is diluted with 256 ml of water and stirred at room temperature for 1 hour. The pH of the solution (8.2) is then brought to 6.4 by adding concentrated sulfuric acid. The solution is then concentrated to 100 ml and acidified to pH 2 by adding 1 M sulfuric acid, and is extracted three times with ethyl acetate. The organic phases are combined, dried over anhydrous sodium sulfate and evaporated to dryness under vacuum. The residue is purified by chromatography on a silica column (elution: chloroform/acetic acid, 95:5). In this manner, 4.7 g of N-maleoyl-6-aminocaproic acid are obtained.

Workup

  1. concentrationThe solution is then concentrated to 100 ml
  2. additionby adding 1 M sulfuric acid
  3. extractionis extracted three times with ethyl acetate
  4. dry with materialdried over anhydrous sodium sulfate
  5. customevaporated to dryness under vacuum
  6. customThe residue is purified by chromatography on a silica column (elution: chloroform/acetic acid, 95:5)

Sources & evidence

ORD record
ord-efc0afd521b14e22a2ad36fd7c679c7f
Source dataset
uspto-grants-1991_07
Patent number
US05030620

Reaction notes

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