Acetyl chloride → benzyl N-acetyl-(L)-pyroglutamate

HRID 543251Notes

Reaction equation

HRID 543251 reaction equation
[NH:1]1[C:5](=[O:6])[CH2:4][CH2:3][C@H:2]1[C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:8].[H-].[Na+].[C:19](Cl)(=[O:21])[CH3:20]>C1C=CC=CC=1>[C:19]([N:1]1[C:5](=[O:6])[CH2:4][CH2:3][C@H:2]1[C:7]([O:9][CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=[O:8])(=[O:21])[CH3:20]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 24758Sodium hydrideHCID 2381219Benzyl 5-oxoprolinate

Product 1

HCID 13655552benzyl N-acetyl-(L)-pyroglutamate

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent3×

Procedure

A solution of 61.3 g (280 mmol) of benzyl (L)-pyroglutamate in 400 ml of benzene is added over 2 hours to a suspension of 13.4 g of NaH (280 mmol) in 50 ml of dry benzene. After stirring for one hour at ordinary temperature, a solution of 22.7 g (290 mmol) of acetyl chloride in 150 ml of benzene is run in and the mixture is heated at 55° for 5 hours and then stirred for 24 hours at ordinary temperature, washed with 2×150 ml of water, dried and evaporated. The product is distilled under reduced pressure; boiling point=150°-60° C. (0.25 mm Hg). This gives 60% of a pure product of Rf=0.63 (A).

Workup

  1. temperatureis heated at 55° for 5 hours
  2. stirringstirred for 24 hours at ordinary temperature
  3. washwashed with 2×150 ml of water
  4. customdried
  5. customevaporated
  6. distillationThe product is distilled under reduced pressure

Sources & evidence

ORD record
ord-1ff4797f5c944570a36e8a6a136700e8
Source dataset
uspto-grants-1987_04
Patent number
US04661512

Reaction notes

Loading…