6-Aminohexanoic Acid → ethyl 6-aminohexanoate

HRID 1070375Notes

Reaction equation

HRID 1070375 reaction equation
[NH2:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]([OH:9])=[O:8].[C:10]1(C)C(S(O)(=O)=O)=CC=C[CH:15]=1>C(O)C>[CH2:10]([O:8][C:7](=[O:9])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2][NH2:1])[CH3:15]

Participants

4

Reactant 2

HCID 5646-Aminohexanoic AcidHCID 69252-Methylbenzenesulfonic acid

Product 1

HCID 406972ethyl 6-aminohexanoateYield 204.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of ε-aminocaproic acid (70.0 g, 533.8 mmol), toluenesulfonic acid (111.7 g, 1.1 eq.) and ethanol (1.6 L) was heated to reflux for 20 hours. Thereafter, TLC (CH2Cl2/EtOH/TEA, 85:10:5) revealed complete conversion. The reaction mixture was concentrated until solids started to precipitate. The precipitation was driven to completion by adding diethyl ether (1.5 L). The white solid was filtered, washed with diethyl ether, and dried in vacuo affording 174.0 g (98.3%) of a white powder. 1H NMR: (200 MHz, CDCl3): δ 7.47 (d, 2H, J=8.2 Hz), 7.10 (d, 2H, J=8.2 Hz), 4.02 (q, J=7.0 Hz), 2.79-2.65 (m, 2H), 2.28 (s, 3H), 2.25 (t, 2H, J=7.0 Hz), 1.16 (t, 3H, J=7.0 Hz), 1.49 (dt, 4H, J=7.6, 7.0 Hz), 1.29-1.22 (m, 2H). 13C NMR: 173.4, 145.6, 138.8, 128.9, 126.1, 60.4, 39.4, 33.9, 27.3, 25.9, 24.6, 21.5, 14.8.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 20 hours
  3. concentrationThe reaction mixture was concentrated until solids
  4. customto precipitate
  5. customThe precipitation
  6. additionby adding diethyl ether (1.5 L)
  7. filtrationThe white solid was filtered
  8. washwashed with diethyl ether
  9. customdried in vacuo

Sources & evidence

ORD record
ord-349256dabc334c84a2c49d80fb7b2e9b
Source dataset
uspto-grants-2005_06
Patent number
US06902900B2

Reaction notes

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