Triethylamine → ethyl N-carbethoxyvalerimidate

HRID 1681936Notes

Reaction equation

HRID 1681936 reaction equation
[C:1](=[NH:9])([O:6][CH2:7][CH3:8])[CH2:2][CH2:3][CH2:4][CH3:5].C(N(CC)CC)C.Cl[C:18]([O:20][CH2:21][CH3:22])=[O:19]>C(Cl)Cl>[C:18]([N:9]=[C:1]([O:6][CH2:7][CH3:8])[CH2:2][CH2:3][CH2:4][CH3:5])([O:20][CH2:21][CH3:22])=[O:19]

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 10928Ethyl chloroformateHCID 12283340Ethyl valerimidate

Product 1

HCID 53930077ethyl N-carbethoxyvalerimidateYield 70%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 6.5 g (50.3 mmol) of ethyl valerimidate (free base) in 90 mL of dry CH2Cl2 was treated with 7.71 mL (5.60 g, 55.3 mmol) of triethylamine. The resulting solution was stirred under N2 at -10° C. in an ice salt bath as a solution of 4.81 mL (5.46 g, 50.3 mmol) of ethyl chloroformate in 10 mL of CH2Cl2 was added dropwise over 25 minutes. Upon completion of the addition, the cooling bath was removed, and the mixture was stirred at room temperature for 2 hours. Next, the solvent was removed by evaporation in vacuo. The residue was taken up in hexane and filtered to remove triethylamine hydrochloride. Concentration of the filtrate yielded 7.08 g (70%) of the product as a yellow oil, suitable for use in the next step without further purification. NMR indicated a mixture of syn and anti isomers. TLC (98:2 CH2Cl2 -MeOH) showed a close pair of spots, Rf 0.48, 0.52. 1H NMR (200 MHz, CDCl3, ppm): δ 0.86 (distorted t, J=7.5 Hz, 3H), 2.15-2.35 (m, 8H), 2.4- 2.65 (m, 2H), 2.19, 2.35 (t, J=7.5 Hz, 2H total), 4.0-4.2 (m, 4H). EI-MS: m/e 201 (M+).

Workup

  1. additionwas added dropwise over 25 minutes
  2. additionUpon completion of the addition
  3. customthe cooling bath was removed
  4. customNext, the solvent was removed by evaporation in vacuo
  5. filtrationfiltered
  6. customto remove triethylamine hydrochloride

Sources & evidence

ORD record
ord-4ab82bf4c07a49b088b3208a172140f6
Source dataset
uspto-grants-1992_12
Patent number
US05175164

Reaction notes

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